Although Harold Ramis could not make a cameo like his costars from the original Ghostbusters due to his death in 2014, you can see a bust of Harold just outside of Erin's university office near the beginning of the film.

Chris Hemsworth was concerned having to face off against three funny women for the interview scene as he doesn't consider himself much of an improviser, but when the time came he improvised the bit with the lens-free glasses and the Mike Hat line among others.

At one point Erin proclaims: "Books can't fly and neither can babies". Both happened in the original Ghostbusters (1984) and Ghostbusters II (1989).

The movie is dedicated to Harold Ramis, as mentioned in the final credits.

After Erin comes to Abby's lab and announces that she has been fired, Abby says, 'Unlike Columbia, this institute is 100% behind us.' This is a reference to Ghostbusters (1984), where Columbia University allowed its facilities to be used for filming as long as its name was never mentioned.

In some of the posters featuring Holtzman, on her proton pack is the number 2206. This is the same number as Dana Barrett's apartment in Ghostbusters (1984).

When Erin Gilbert is giving her presentation on quantum physics, she writes equations on a board, one of which spells out the equation [Pa/RA(NO+RM)alS+UD1ies/Lab]com. If you type this formula in a Google search you will be redirected to a Ghostbusters marketing website, an Easter egg present in the film. As of October 2017 the website has been taken offline.

During the 1990s, Dan Aykroyd's concept for a third Ghostbusters film revolved around the Ghostbusters traveling to an alternate, hellish version of New York City. Columbia Pictures balked at the proposed $150m budget. Ultimately, Ghostbusters (2016) ended up with a $144m budget, although inflation means it cost less than Aykroyd's proposed sequel.

The studio didn't want the scene of Shanks flipping off the women as they were worried it would "scare away families." Early internet comments presumably before the focus became some fans complaining about the female cast begged Paul Feig to make it family friendly like the original Ghostbusters (1984). "If you watch the original they swear constantly, they smoke constantly, and then there's fellatio from a ghost. So people remember what they want to remember."

The role of Patty Tolan, played by Leslie Jones, was originally written for Melissa McCarthy. Paul Feig realized that McCarthy had already played similar characters in his previous films, explaining "I wanted to unleash Leslie on the public in the same way we unleashed Melissa on the public in Bridesmaids (2011), with a very showy role."

Paul Feig calls Zach Woods "literally the best improviser I've ever worked with, across the board." He was cast even before the Ghostbusters themselves.

Jason Reitman, son of original Ghostbusters (1984) director Ivan Reitman, was asked in an interview if he would consider directing the reboot. Reitman joked that, based on his existing work, his version of the film would just be people talking about ghosts. In 2019, 3 years after this film's release Jason Reitman announced he was helming an all new Ghostbusters movie. A sequel to the Original.

When possessed Kevin shows the Ghostbusters the glory days of New York City and summons ghosts, there's an advertisement saying "That's a big" and showing a Twinkie -- a reference to Spengler's 35-foot-long, 600-pound Twinkie metaphor in the original Ghostbusters (1984).

When the Ghostbusters open the container with the ghost for Dr. Martin Heiss, he jokingly calls the ghost "Casper" in reference to the children's cartoon character "Casper, the friendly ghost". The creators of Ghostbusters (1984) were sued by the owners of the "Casper" properties for $50 million plus the destruction of the film prints. because their logo looked too similar to their character "Fatso", a member of "The Ghostly Trio". But in 1986 the case was ruled in favor of "Ghostbusters". Nevertheless the live-action adaptation of Casper (1995) featured a cameo of Dan Aykroyd as Ghostbuster Ray Stantz.

In the end credits, special thanks are given to "GB Superfan" Ryan E. Kemp who died in October 2015. Kemp had met with Paul Feig on two occasions and was positive about the prospect of this reboot.

At one point in the movie, Holtzmann says "they are heavier than you think" with regards to the proton packs. During the filming of the first two original Ghostbuster movies, the actors often complained about the weight of the proton packs.

When the Ghostbusters' early version of the proton pack fails and gets crushed by the subway train, the sound it emits is the same sound of the Millennium Falcon hyperdrive failing in Star Wars: Episode V - The Empire Strikes Back (1980).

Chris Hemsworth's big possessed dance sequence was the toughest scene Paul Feig had to cut from the theatrical version.

The ghost Slimer got his name in the cartoon series The Real Ghostbusters (1986). His name is not spoken in any of the movies, but appears in the credits of Ghostbusters II (1989).

Erin has an Apker Award from the American Physical Society on the wall in her office. This is a real annual award for outstanding achievements in physics by an undergraduate student.

Producer Dan Aykroyd revealed in an interview: "You know, the director, he spent too much on it, and he didn't shoot scenes we suggested to him, several scenes that were gonna be needed and he said, no, we don't need them, and then we tested the movie and they needed them and he had to go back... about 30 to 40 millions in re-shoots, so... he will not be back on the Sony line any time soon".

In the late 2000s, Harold Ramis and Dan Aykroyd supervised a script for a third Ghostbusters film written by Year One (2009) co-writers Gene Stupnitsky and Lee Eisenberg. Bill Murray later said, in an interview with GQ, that he never read the script after Year One was a commercial and critical failure. Later, Etan Cohen wrote a draft. Aykroyd vehemently denied a rumor that Murray shredded the script. During an appearance on the Howard Stern Show, Murray admitted he had not read that draft either.

There is also tribute to John Candy, who was originally approached to play Louis in the original Ghostbusters (1984) but turned down the part. The Dean of Higgins university, where Abby and Holtzmann work, is named Thomas Shanks. Tommy Shanks was one of John Candy's characters in SCTV (1976). John Candy is also featured in the original Ghostbusters music video.

When the Ghostbusters are driving to the rock concert, they pass the New York Public Library, where the original opens with. They also pass the "docking" area where Ecto-1 pulled out of after their meeting with the mayor in the original Ghostbusters (1984).

During the climax, the number 1984 is seen on Jillian Holtzmann's Proton pack. 1984 the year the original Ghostbusters (1984) was released in theaters. It is also the year in which Kate McKinnon was born.

Was denied permission to be screened in China.

Holtzmann's hairstyle and glasses resemble her counterpart Egon from Slimer! And the Real Ghostbusters (1988).

Holtzman calls Pringles potato chips "salty parabolas". The shape of a Pringles potato chip really is a hyperbolic paraboloid or a saddle surface. Parabolas are two-dimensional.

Emma Stone turned down an offer to star in the movie. She stated that while she liked the script, she did not want to commit to another potential series so soon after appearing in The Amazing Spider-Man (2012) and The Amazing Spider-Man 2 (2014).

The character Jillian Holtzmann wears a necklace throughout the film in the shape of a U with a screw going through it. The Ghostbusters-inspired "Holtzman's Screw U" necklace pendant has since been created and is sold online.

When Erin first visits Abby at Higgins University, a sign on the door to Abby's lab reads "Do not write (stupid) things on this door!". This is a call back to the original Ghostbusters (1984) film where on the door of the Ghostbusters university lab someone has written "VENKMAN BURN IN HELL".

The four main cast members all joined the movie because they themselves were fans of the original Ghostbusters (1984) movie (and in Melissa McCarthy's case, The Real Ghostbusters (1986)).

Rowan has a certificate for a Hughes Medal on his wall. This is an actual award that is given out biennially by the Royal Society of London "in recognition of an original discovery in the physical sciences, particularly electricity and magnetism or their applications".

In an interview with 'Den of Geek', Paul Feig revealed that the first cut of the movie was 4 hours and 15 minutes long.

Even though the movie is set New York City, most of the filming was done on locations in and around Boston. These locations include Chinatown in Boston, Easton, a hangar and runway on the old South Weymouth Naval Air Station (now Union Point condo complex) in South Weymouth, Massachusetts, and the old Everett High School in Everett, Massachusetts. The runway set at Union Point was made to appear as a 2-block stretch of Times Square (42nd Street to 44th Street), complete with street lights, lots of green screens and the focal point being a two-story structure with a office building feel to it. The crosswalks the production painted on the asphalt are currently still visible on the runway.

Gertrude Aldridge was based on Lizzie Borden.

Eliza Dushku was floated around as one of the members of the team with her name cropping up in some early credits works and the actress herself even dressing as a Ghostbuster for Halloween.

The extended cut features an additional fifteen minutes, and Paul Feig talks about the reasoning behind cutting bits for a theatrical release. Oftentimes the details are dropped in favor of pacing, and it's not always the best choice. "That's why it takes us like half a year to edit and do test screenings to find what we need and what we don't need." He points out later that the energy of a theatrical cut should play to the room while a version made for home video is designed for viewers no longer dependent on others' laughter.

Kristen Wiig had to be slimed twice as the first one missed her face and the second blast knocked her wig off. Instead of taking another two hours to reset and try again they just cut the two together and added some digital slime for good measure.

Slimer was created with an actual puppet. An early script gave him an origin as a gangster who killed someone in New York City's Rainbow Room before dying himself.

The equipment test in the alley was added in re-shoots. It was suggested by Melissa McCarthy. The alley was infested with rats.

As of January 2019 this film holds the title for 'most disliked' trailer ever on YouTube.

Aldridge Mansion is located at Boston University where it functions as their Alumni house, so the skyline behind it is added digitally.

The creepy parade balloons are based on actual Macy's parade balloons from long ago.

The joke of Ed Begley Jr. being Ed Mulgrave Jr. as opposed to Ed Mulgrave Sr. is an homage to Ed Begley Sr. and Ed Begley Jr who are both actors.

Aldridge Mansion is loosely based on the Old Merchant's House on 4th street in Manhattan, which is also a museum open to the public.

The studio had wanted to make Ghostbusters 3 for many years. When Dan Aykroyd was asked many times about the third film, his answer was always yes - on condition that all principal Ghostbusters (1984) cast members including Ivan Reitman (who directed the first two films) return. The only main problem according to the main players was Bill Murray himself, who shows a lack of interest in reprising the role of Peter Venkman. However, the cast did reprise their roles in the 2009 video game, which is unofficially considered the third film and takes place two years after the events of Ghostbusters II (1989). According to Reitman, when he met Murray in 2011, Murray already had shown loss of interest when the subject was brought up although there was no script at that time. The passing of Harold Ramis in early 2014 was the final straw that two weeks after that Reitman announced that he didn't want to direct it, resulting in Ghostbusters 3 being canned.

Kate McKinnon designed her character Holtzmann's hairstyle. Contrary to some internet speculation it is not based on the cartoon Egon's hair.

Paul Feig and Chris Hemsworth have the same agent, and that's how he got word that Hemsworth was interested in joining the film.

The concert hall scene had an earlier iteration that took place at Comic-Con. "I just love the idea that Comic-Con's the one place that you can walk in fully-armed and everybody just thinks 'oh it's your costume!'"

Anna Faris, Alyssa Milano, and Eliza Dushku were rumored or mentioned by Dan Aykroyd as potential female Ghostbusters, before the project was a reboot.

A poster of the Boris Karloff film Isle of the Snake People (1971) is on display when the villain recreates the glory days of 1970s New York City. Such a recreation is complete with movie posters (Taxi Driver (1976)), neon signs, naughty businesses, billboards advertising products from the time period. The "War Is Over (If You Want It)" billboard is also seen; John Lennon and Yoko Ono paid for these billboards to be put up during the Vietnam War as a form of protest against the war. Lennon's 1971 single "Happy Xmas (War Is Over)" accompanied the billboards.

The painting of Gertrude Aldridge bears a strong resemblance to the painting of Vigo the Carpathian from Ghostbusters II (1989).

Jennifer Lawrence and Rebel Wilson were considered by director Paul Feig for roles in the movie.

Higgins University is believed to be named after Steve Higgins who plays the dean. Higgins is a writer and producer on Saturday Night Live (1975). Director Paul Feig denies this, saying the name was chosen long before casting.

During the title sequence, there is a shot of the library of Columbia University. Parts of Ghostbusters (1984) were filmed at Columbia University.

Four of the cast members, Kristen Wiig, Leslie Jones, Kate McKinnon, and Cecily Strong have been Saturday Night Live (1975) cast members. At the time of release, Melissa McCarthy had also hosted SNL four times. Of the original cast, Bill Murray and Dan Aykroyd were also SNL stars, while Harold Ramis was a writer for the Canadian sketch show SCTV (1976), co-starring Rick Moranis.

Some scenes were filmed at the Ames family Stone Mansion at Borderland State Park in Massachusetts, where the Stone Lodge/Lake scenes for Shutter Island (2010) were filmed.

Paul Feig originally envisioned an opening involving "an old guy getting electrocuted" but says they "mercifully" threw it out in favor of Katie Dippold's suggestion for a more iconic, old-NY feel.

The car that Melissa McCarthy's Abby falls onto is her character's car in The Heat (2013).

The car the Ghostbusters use which Patty got from her uncle is a 1983 Cadillac funeral coach 'Ecto-1'.

Leslie mentions that Rowan's clothes make him look like Captain Kirk. Chris Hemsworth played Captain Kirk's father in Star Trek (2009).

Despite some avoiding the movie at the theaters, it still found some success. In addition to inspiring many fans who appreciated seeing female scientists portrayed on the big screen, the film and the cast were all nominated for several awards, and a few took some home. Melissa McCarthy won a People's Choice Award for Favorite Comedic Movie Actress. The film also won Favorite Movie at the 2017 Kids' Choice Awards, beating huge blockbuster titles like Rogue One: A Star Wars Story (2016), and Favorite Movie Actor and Favorite Movie Actress (Chris Hemsworth and Melissa McCarthy).

Corvette Summer is one of Paul Feig's favorite movies, and it stars Annie Potts as a character named Vanessa. Her cameo here is as a character named Vanessa.

This will be the 4th time Michael McDonald (Jonathan the Theater Manager) appears in a movie starring Melissa McCarthy. He also appeared in The Boss (2016), Spy (2015) and The Heat (2013).

Erin notes that her red hair dye is called "Garfield." Though she says "the President [James A. Garfield], not the cat," the cat has a Ghostbusters connection of its own: Both Bill Murray and Lorenzo Music have shared the roles of Garfield the cat and Peter Venkman the Ghostbuster.

Mindy Kaling mentioned the idea of an all-female remake of Ghostbusters (1984) in her 2011 book "Is Everyone Hanging Out Without Me? (And Other Concerns)." She is not, however, involved with the making of this film.

Erin wears an MIT class ring on her right hand, visible in close-ups and in another scene she wears an MIT sweatshirt.

A third Ghostbusters film had been stalled in development for nearly 25 years, until director Paul Feig pitched a reboot instead.

Was released just five months after Valentine's Day 2016, which in Ghostbusters II (1989) a psychic predicted to be the day the world ended.

Paul Feig knew Kate McKinnon from Saturday Night Live (1975) and had met her at after-parties, but it wasn't until he read in an interview that one of childhood dreams was to be a Ghostbuster that he thought to have her come in for the film.

When Chris Hemsworth (an Australian actor) says "you know, an aquarium is like a submarine for fish", this could be a parody of an infamous comment made by Australian politician John Madigan at 02 February 2015 on ABC's "Q&A" program, in which he says "submarines are the spaceships of the ocean".

Katie Dippold wrote all of "that stuff" on the whiteboard behind Erin.

First Ghostbusters film to introduce another ghost of Slimer's kind, a love interest in the form of Slimerette.

The first property viewed, deemed too expensive, is the headquarters in Ghostbusters (1984).

Jillian Holtzmann eats Pringles potato chips as she ghost hunts. In the original Ghostbusters (1984), Venkman has an open bag of Wise chips with him when he meets Walter Peck.

The film features frequent product placement from both Papa Johns Pizza and Coca-cola. However, when the girls are having Papa Johns Pizza for lunch, their soda cups have no label. This is because Papa Johns sells Pepsi products instead, therefore they couldn't be drinking Coke products because it would have been a conflict of corporate interest.

The Chinese restaurant has a 'B' rating from the health department.

The extended cut runs 2 hours and 13 minutes, making this the longest Ghostbusters movie to date.

The Irish Pub in Time Square says "Irish Since 1984", year of the original Ghostbusters (1984).

In early pre-production, Anne Hathaway was reportedly considered for a role. The role was supposedly a doctor named Anna.

The Higgins Institute was named that well before Steve Higgins was cast as its dean. His character name, Thomas Shanks, is a nod to an old SCTV sketch with John Candy.

The Aldridge mansion tour guide mentioned the grandfather clock was put on a lifeboat of the RMS Titanic, a ship which appeared in Ghostbusters II (1989).

Martin Heiss' fashion sense is widely believed to be based on Paul Feig's own flamboyant fashion sense, but Feig denies this.

Kate McKinnon ad-libbed The Wizard of Oz (1939) song lyric "Come out, come out, wherever you are." Paul Feig and Katie Dippold however, did not recognize the reference in the audio commentary, which resulted in further criticism.

The critical and commercial failure of this film forced Sony Pictures to abandon any hopes for a sequel. Instead, they opted to continue the original series' narrative starting with Ghostbusters: Afterlife (2021). This film will ignore the events of the 2016 reboot and instead will serve as a direct sequel to Ghostbusters (1984) and Ghostbusters II (1989).

This film is considered non-canonical.

Spent over $70 million in marketing costs.

First Ghostbusters film not to be directed by Ivan Reitman.

The first Ghostbusters film to receive a PG-13 rating.

They planned a gag for later in the film where a nerd-bro sees the women in uniform and says "Nice vacuums" only to be zapped in the butt by Patty, but they went with the earlier one instead involving the YouTube comments.

The character name Erin Gilbert is in fact a combination of two characters played by Julia Roberts. Erin is based on Erin Brockovich (2000), Roberts' award-winning role, while the last name Gilbert refers to author Elizabeth Gilbert, the author that Roberts played in Eat Pray Love (2010). Gilbert's book is also mentioned in the movie as well.

They got push-back, presumably from the studio, on the flasher ghost for fear it would be offensive. Paul Feig says the trouble started with preliminary artwork that was done including some pieces showing the flasher with "an enormous demon mouth and tongue coming out right where his junk is." This is a rare instance of studio push-back being understandable.

Kevin's motorcycle is a AMF Harley-Davidson SX 175 Aermacchi.

Melissa McCarthy and Bill Murray previously co-starred in St. Vincent (2014).

All four main actresses have been nominated for Emmys for their work on Saturday Night Live (1975). As of August 2018, Kate McKinnon has won two Emmys in the Supporting Actress category and Melissa McCarthy has won one for her Guest actress appearance. Kristen Wiig and Leslie Jones have been nominated but have yet to win.

Paul Feig thinks Kristen Wiig is similar to someone like Chris Farley in that both performers have comedy in their veins. Her current focus on dramatic material made him think she wouldn't be interested in this film, but Wiig actually reached out to Feig to request a role even if it was just a small one.

Melissa McCarthy and Dan Aykroyd previously co-starred together in Tammy (2014).

Five actors who appeared as the crew in Other Space (2015), created by Paul Feig, have roles--ranging from brief cameos to major parts--in the film: Neil Casey, Eugene Cordero, Bess Rous, Karan Soni, and Milana Vayntrub.

Katie Dippold wrote the screenplay. She also wrote the cop comedy The Heat (2013), which also starred Melissa McCarthy.

Bill Murray says "Atta girl!" to Erin Gilbert. He previously said the same thing in Scrooged (1988)

Seward Street Station is fictitious.

The American rock band Fall Out Boy covered the original Ray Parker Jr. song which was used in the main soundtrack of this film. Their version received heavy criticism from fans and critics alike. However, Walk On Moon also covered the song, but being faithful to the original Ray Parker song.

In addition to changing the sex of the main characters the ages of the characters are also changed, from early 30's to mid 40's.

Melissa McCarthy and Kristen Wiig were together on Bridesmaids (2011), also directed by Paul Feig.

The Pringles bit is not an example of product placement. They just think Pringles are funny. By contrast, Papa Johns did pay money to be in the film. (Paul Feig and Katie Dippold make no attempt to defend it.)

The Aldridge Mansion may be named for Ghostbusters (1984) costume designer Theoni V. Aldredge.

The film reunites Justin Kirk and Elizabeth Perkins of Weeds (2005). Their scenes are in the extended version only.

Melissa McCarthy, Zach Woods, Jessica Chaffin, Michael McDonald, Adam Ray, Nate Corddry, and Steve Bannos all worked together on The Heat (2013).

Melissa McCarthy and Cecily Strong previously co-starred together in The Boss (2016).

Kevin's last name is visible on his signed beefcake photos as Beckman, which resembles the last name of Bill Murray's character in the original movies, Peter Venkman.

Steve Higgins (Dean Shanks) and David Allen (Electrocuted Ghost/Sparky) previously starred together in the TV series Higgins Boys and Gruber (1990).

Upon announcement of the film's cast and crew, a heavy controversy erupted among the social media. Fans of the original film series criticized the all-female cast and the choice of Paul Feig as director. The film's IMDb page and official trailer were the primary target of review bombing. This online hate was also hinted in the film, where the Ghostbusters upload their ghost hunting on YouTube to heavy critical backlash.

Paul Feig points out Brian Baumgartner on the commentary but declines to call him "amazing" like he does for every single other person involved in the film's production.

Daniel Ramis: son of Harold Ramis has a small role as a Metal Head outside the concert Rowan attends.

Katie Dippold: Screenwriter plays the real estate agent.

Dominik Garcia: as Mayor Bradley's daughter, sitting with him when Erin barges into the Lotus Leaf warning him to evacuate the city.

Paul Feig: the voice on the other end of the walkie talkie that tells Rowan to go clean the bathrooms.

Paul Feig: as the voice of the Ghost Jumpers narrator. He also drew the ghost with the giant boobs.

Bill Murray's character Martin Heiss does not die in the movie. In the movie tie-in book, "Ghosts from Our Past: Both Literally and Figuratively: The Study of the Paranormal", Heiss writes a foreword and states that the Ghostbusters are not frauds and had he believed them, he wouldn't have suffered large medical bills as a result of being knocked out of the window by a ghost.

Original Ghostbusters (1984)/Ghostbusters II (1989) cast members - Bill Murray, Dan Aykroyd, Ernie Hudson, Annie Potts, Sigourney Weaver and even Harold Ramis all have cameos in the movie. Early on in the movie version of Ramis can be seen in the form of a bronze bust in the hallway outside Kristen Wiig's office. Aykroyd confirmed a cameo appearance on his Facebook and Twitter pages, although the post was later deleted. Hudson and Weaver's cameos were confirmed by director Paul Feig on Twitter, after the first two cameos leaked to the press. Rick Moranis, who has long since retired from acting, was also offered a chance to cameo, but declined.

Original Ghostbusters (1984) cast cameos: Sigourney Weaver briefly appears as Holtzmann's mentor Rebecca Gorin. Ernie Hudson, as an undertaker Bill and uncle of Tolan, Bill Murray, as Martin Heiss, accuses the Ghostbusters of being fraudsters. Dan Aykroyd, an all knowing cab driver. Annie Potts appears as a desk clerk, snapping her 1984 line, "What do you want..."

Ghosts From Our Past is available to buy on Amazon and the authors are Erin Gilbert And Abby L. Yates, two of the main characters of the movie. This tie-in book is actually written by Andrew Shaffer, who is credited as 'book editor'. It is a revised version of the one seen in the movie, as it contains various references to events of the film and why the first line is not "This book is not a joke" (this line was not in the script Shaffer worked from but was ad-libbed during filming). The photo on the back is also different from the movie, but a printable dust-cover that resembles the movie version can be downloaded from the book's official site (

At the end of the rock concert scene, Holtzmann grabs a guitar and smashes it on the stage in her excitement. This was improvised by Kate McKinnon on set. Paul Feig had to quickly stop her from smashing the real guitar, but liked the idea enough to allow more set-ups with a fake prop guitar.

Dan Aykroyd's character, a taxi driver, says before driving off, "I ain't afraid of no ghosts." This is a nod to the original Ghostbusters (1984) theme song. He also calls the ghosts "Class 5 floating vapors." which is almost a word for word match for Ray's original description of Slimer: "A class 5 full-roaming vapor."

Ernie Hudson makes his cameo appearance at the end of the movie - playing Patty Tolan's uncle - outside the original Ghostbusters firehouse. In Ghostbusters (1984), this is where his character Winston Zeddemore makes his first appearance.

Kevin says "Ghostbusters, what do you want!" on answering machine, just like Janine does in the original Ghostbusters (1984) as she complains about working hard.

In an after credits scene, Patty Tolan is running through a tape player checking for ghostly phenomena. Suddenly, she looks up from the machine and says she thinks she's got something to the rest of the team. When they all look, she asks, "What's Zuul?" They all shrug in confusion. Zuul is one of the primary evil spirits from the original Ghostbusters (1984).

When the Ghostbusters are getting ready to fight the ghosts in New York, one of the billboard ads shows a large Twinkie with the slogan, "That's a big Twinkie." This is a direct quote of the famous line in the original Ghostbusters (1984) by Ernie Hudson.

During the exorcism scene, Patty can be seen swinging a metal tube directed towards Abby. This metal tube is actually one of the exterior pieces seen on the back side of the Delorean in the Back To The Future trilogy.

Director Paul Feig encouraged improvisation among leading actors as well as having them incorporate some of their real-life characterizations into their characters. Some ended up in the film (the ladies responding to the haters and trolls after their first ghost video on Youtube; Abby (Melissa McCarthy) liking the film Road House (1989), which in real life is one of McCarthy's favorite films; at the end of the film in a deleted scene Jillian mentions that Erin and herself are dating: this indicates that she is a lesbian, which Kate McKinnon actually is in real-life) .

The containment unit shown near the end of the movie shows a "D. Barrett" and a "V. Clortho" on its monitor. Dana Barrett is Sigourney Weaver's character in Ghostbusters (1984) and Vinz Clortho is the Keymaster, the entity that possessed Louis Tully. As Rick Moranis has long since retired from acting, this was a way to include him in the film.

Slimer eating hot dogs from a street vendor is not only a reference to his original appearance in the first Ghostbusters (1984), but it also references Kevin's earlier drawing, which he describes as a ghost levitating a hot dog.

A number of actors from Ghostbusters (1984)/Ghostbusters II (1989) appear in this one - Bill Murray (Peter Venkman), Dan Aykroyd (Raymond Stantz), Sigourney Weaver (Dana Barrett), Annie Potts (Janine Melnitz) and Ernie Hudson (Winston Zeddmore).

Not counting this movie's mid- and post-credit scenes, Ernie Hudson delivers the final line in both this movie and the original Ghostbusters (1984).

When Abby demands that Rowan shows himself, he asks "What form would you prefer I take?" In Ghostbusters (1984), Gozer gives the Ghostbusters the choice to "Choose the form of their destructor."

In the film's 3-D version, it is letterboxed and certain 3-D elements show over top of the black bars, with the exception of the scene in which Erin jumps into the portal, which fills up the whole screen. The same goes for the Blu-ray release.

Paul Feig is unapologetic about the ladies shooting Rowan's large ghost form in the nuts, and he points out that it was entirely his decision not Katie Dippold's. She thanks him for saying that because many have assumed it was her choice as a way to stick it to the guys.

Bill Murray's character Martin Heiss is a skeptic and debunker of paranormal activity. His character of Dr. Peter Venkman in the original movies was a scientific charlatan who also did not believe in ghosts until he saw one personally. By contrast, all of the new Ghostbusters consider themselves serious scientists who believe in paranormal phenomena.

The hearse the Ghostbusters drive has the license plate "ECTO 1". The motorcycle that Kevin rides after being possessed has plates "ECTO-2".

Paul Feig regrets keeping Ozzy Osbourne's cameo so secret, because it meant keeping him backstage until the roomful of extras was emptied. "So everybody who was there, I apologize."

They didn't know until the day before filming his cameo whether or not Bill Murray would be doing the cameo.

Abby and Erin's hair inexplicably turning white towards the end comes from The Real Ghostbusters: The Hole in the Wall Gang (1987).

In the original Ghostbusters (1984) the Traveller appears because Ray pictured the Stay Puft Marshmallow Man. As Holtzman is being crushed by the inflatable Stay Puft Marshmallow Man, she mentions that this is exactly how she pictured her death.

In an October 2015 Entertainment Weekly article, Dan Aykroyd confirmed that the film's cameo appearances by the original cast have them playing different characters. This is in line with director / co-writer Paul Feig's comments before filming, in which he stated that he did not want to make a film in a universe where people were already used to seeing ghosts (such as the "original" Ghostbusters (1984) timeline).

The much maligned first trailer opened with a piano version of the Ghostbusters theme. The opening notes of the same recording are heard when Kevin, possessed by Rowan, propels a grand piano at the Ghostbusters.

During the end credits, Holztmann says she's made some new Ghostbuster equipment. She then says she doesn't know where the ghosts are after they are captured but she thinks it might be Michigan. Paul Feig is from Michigan.

The film cast includes six Oscar nominees: Bill Murray, Dan Aykroyd, Sigourney Weaver, Andy Garcia, Melissa McCarthy and Kristen Wiig.

The appearance of the Stay-Puft Marshmallow Man as a parade balloon is derived from The Real Ghostbusters: The Revenge of Murray the Mantis (1987).

While closing the portal, two Ghostbusters rescue the other two by pulling them back from the "other side." While being pulled through, their hair turns white. This is very similar to the scene of rescuing the little girl in Poltergeist (1982).

When Patty slaps the ghost out of Abby, Abby say, "That's going to leave a mark." She is possibly quoting John Candy from Spaceballs (1987). John was originally going to play Louis Tully in Ghostbusters (1984) before the movie was delayed and recast.

The second Ghostbusters film in which Slimer is shown driving a vehicle, the first being Ghostbusters II (1989).

When Holtzmann is fighting Rowan at the Mercado hotel she beckons "Come out, come out wherever you are." which was first line of Glinda's song in The Wizard of Oz (1939).

Chris Hemsworth and Sigourney Weaver also both appeared in the movie The Cabin in the Woods (2011). They did not appear onscreen together in either film.

Near the end of the film when Rowan becomes a giant ghost, his face bears a very strong resemblance to Ray from the original movies. In Ghostbusters (1984) Ray accidentally thought of the Stay Puft Marshmallow Man during a similar scenario, and he is also considered the heart and soul of the Ghostbusters team.

Bill Murray liked the idea of basing his character's look on Quentin Crisp.

Charles Dance previously appeared in Alien³ (1992) with original Ghostbusters (1984) cast member Sigourney Weaver, who also makes a cameo.

Sigourney Weaver and Kristen Wiig appeared together in Paul (2011) five years previously.

The cinematographer for this film, Robert D. Yeoman, frequently works with Wes Anderson. Bill Murray, who has a cameo in this film, also often works with Wes Anderson.