Jamie Lee Curtis considers the film a thank you note to her fans. Curtis: "Without that early career, I truly don't think I would have been an actor."

During the scene where Norma is leaving, she stands in front the car from Psycho (1960). The music playing in the background at this part is also from Psycho. Janet Leigh, who plays Norma, played Marion in Psycho. The license plate on the car is also the same as the second car Marion buys in Psycho, NFB 418, which are Norman Bates' initials.

Kevin Williamson's original treatment for H20 included a scene in which Halloweens 4, 5, and 6 are acknowledged as being in continuity and canon. The scene does exist and involves a bitchy student at Keri/Laurie's school giving a class report on the Haddonfield murders, going into great detail about Jamie Lloyd, Danielle Harris, and J.C. Brandy's character from Halloween films 4 through 6. The student talks about Jamie losing her parents in an auto accident, as was the explanation in those sequels for Laurie Strode's absence. (In fact, the only reason for Laurie to be in the Witness Protection Program with her son under an assumed name as "Keri Tate" at all was because the original story for "H20" was conceived like this, with 4, 5, and 6 in continuity. Williamson was then required to create an explanation for Laurie's "death" in the previous movies and her subsequent resurrection.) The student's report chronicles Jamie's being hunted and eventually killed by her uncle, Michael Myers. Upon hearing this oral presentation in the classroom, a grief-stricken Keri/Laurie then retreats to a restroom and vomits. This scene was omitted from the final cut of the film.

Even after 20 years, Jamie Lee Curtis said that seeing Michael Myers on set still scared her.

John Carpenter was originally in the running to be the director for this particular follow-up since Jamie Lee Curtis wanted to reunite the cast and crew of the original to have active involvement in it. It was believed that Carpenter opted out because he wanted no active part in the sequel; however, this is not the case. Carpenter agreed to direct the movie, but his starting fee as director was $10 million. Carpenter rationalised this by believing the hefty fee was compensation for revenue he never received from the original Halloween, a matter that was still a point of contention between Carpenter and Akkad even after twenty years had passed. When Moustapha Akkad balked at Carpenter's fee, Carpenter walked away from the project.

LL Cool J's line, "Comb your hair!" was ad-libbed, inspired by Josh Hartnett's messy haircut.

LL Cool J had always been a fan of the Halloween movies. His mother took him to see the original when he was just nine years old.

Before he knew Jamie Lee Curtis was involved, Josh Hartnett wasn't sure he wanted to audition. "Halloween 7? Is that going straight to video, or is that going straight to hell?"

When Jamie Lee Curtis' character says, "go down the street to the Beckers..." this was supposed to refer to the line from Halloween (1978) , "go down the street to the McKenzie's house..." The name was changed to Becker, which was the last name of Drew Barrymore's character in Scream (1996).

The original working title for the film was Halloween 7: The Revenge of Laurie Strode.

P.J. Soles was originally approached for the role of Keri Tate's/Laurie Strode's secretary. Soles never gave a straight answer as to what she wanted to do, skeptical about returning to the series as someone completely different than her character Lynda, originally killed off in Halloween (1978). She eventually lost the role to Jamie Lee Curtis's mother, Janet Leigh, who was approached after not getting an answer from Soles.

Janet Leigh's first role in a feature film for 18 years. Her previous theatrical film was The Fog (1980), which also starred her daughter, Jamie Lee Curtis.

During one of the scenes at school, Charlie (Adam Hann-Byrd) tells John (Josh Hartnett) that "20 years from now, you're still gonna be living with her, probably running some weird motel, out in the middle of nowhere." This-of course-is a reference to Psycho (1960) starring Jamie Lee Curtis's mother, and fellow 'H20' alumnus, Janet Leigh.

Jamie Lee Curtis admitted she only did the movie for the paycheck, stating that it started out with the best intentions, "but it ended up being a money gig, the film had some good things in it. It talked about alcoholism and trauma, but I just did it for the money".

On the television in the girls' room a clip from Scream 2 (1997) is showing, reciprocating numerous Halloween (1978) references and clips in Scream (1996). However, according to producer Moustapha Akkad when the scene was filmed, the girls were actually watching So I Married an Axe Murderer (1993), making an entirely different joke: a movie featuring Michael Myers had its characters watching Mike Myers. The clip was changed to Scream 2 (1997) in post-production.

During the credits in the prologue, Dr. Samuel J. Loomis' dialog from the first film about Michael's incarceration is heard. The studio, instead of recovering the original audio from the original scene, decided to use a sound-alike actor named Tom Kane to provide the voice-over.

The director and writers decided to treat this movie as if Halloweens 3-6 never took place. This was a decision made to keep the plot simple and focus on the Laurie character.

The shortest "Halloween" movie in the series, with a run time of 86 minutes.

In the scene where Janet Leigh's character speaks to Laurie, she says "If I may offer some maternal advice..." Laurie is played by Jamie Lee Curtis, Janet Leigh's daughter.

One of the masks used from Halloween 6: The Curse of Michael Myers (1995), was used for the first scene appearance of Michael Myers.

In certain scenes, Michael can be seen wearing two different masks. The director decided well into production, to go with a different mask, so certain scenes were re-shot. Some scenes with the original mask can still be seen, and in one shot it had to be altered with CGI to replace Michael's old mask with the new one.

In the original Halloween (1978) when Laurie is in class we hear the teacher talking about fate. In Halloween H20 when Laurie is teaching, Molly Cartwell gives an answer about fate.

According to Halloween 6: The Curse of Michael Myers (1995) writer Daniel Farrands, who wrote an early draft of the film, said there was originally a scene scripted and supposedly filmed where a student in Laurie's class does a report on a book called "The Halloween Murders", in an effort to tie all the movies together. This was dropped however, when it was decided by the director and producers to ignore "H4-6" so as to concentrate more on the Laurie Strode aspect of the story.

The line "everyone is entitled to one good scare" is said by Norma to Laurie. Sheriff Brackett (Charles Cyphers) originally said it in the first Halloween (1978).

Director Steve Miner also directed two films in another popular horror series: Friday the 13th Part 2 (1981) and Friday the 13th Part III (1982).

This film's sequel Halloween: Resurrection (2002) is so reviled by fans of the "Halloween" franchise, some wish to ignore it as if it never existed, and view this as the serie's finale.

For reasons unknown, on the Halloween: 25 years of terror DVD, John Carl Buechler and Greg Nicotero of KNB FX revealed that this movie uses 4 completely different masks throughout the movie. The first one from John Carl Buechler resembled the one from Halloween 6. However, the producers were not satisfied so they called in Greg Nicotero and had him make a new mask and filming resumed using it. Then again this masked was replaced by another one, at one point a CGI mask is also used. Watching the movie, it is fairly obvious to see that mask change throughout.

The newspaper clippings in the beginning were meant to be the only link to Halloween's 4-6 after the scene in the classroom was cut, and would have included clues such as "Mysterious cult kept murders hushed up in Haddonfield" and "Jaime Lloyd missing" with dates such as 1995 and 1989, in the end only one "headline clue" was left in, a pair of bloody scissors that may have been the ones used to kill Rachel Carruthers in the fifth film.

Jamie Lee Curtis has played Laurie Strode in films released in five different decades from the 1970s to the 2010s: Halloween (1978), Halloween II (1981), Halloween H20: 20 Years Later (1998), Halloween: Resurrection (2002) and Halloween (2018).

In the film, a clip of Scream 2 (1997) is shown. Chris Durand, who plays the killer Michael Myers, had an uncredited role as a stunt double for the masked killer in 'Scream 2.'

Michelle Williams signed on never having seen any of the Halloween movies.

The phrase "Do as I say" is spoken twice by Laurie while escorting the students to safety. This same line was spoken to the children in the original Halloween movie.

A statue of Butterball, the cenobite from Hellraiser, can be seen on Jimmy's porch when the nurse knocks on his door.

Jamie Lee Curtis nickname for Chris Durand (Michael Myers) during filming was "Shapey".

Originally, Sarah (Jodi Lyn O'Keefe) was written as a bitchy student who was dating Mitch (John Tate's original name) she was also supposed to be the student who wrote a paper on the Haddonfield murders which would have connected 4-6 to H20.

When Molly is in the classroom, she spots Michael outside the school and gets interrupted by the teacher, and when she looks again he is gone, just like Jamie Lee Curtis did in Halloween (1978).

Jamie Lee Curtis originally wanted Laurie's life to be in a shambles at the start of the film. Executive producer Kevin Williamson convinced her that Laurie should have more to lose.

Contrary to popular belief, Kevin Williamson was in fact not the original writer of the film. Originally, Robert Zappia was hired to pen 'Halloween 7,' which was planned to go direct-to-video after the modest box office performance of Halloween 6: The Curse of Michael Myers (1995). Zappia's original script was set in a fenced-in boarding school as does the finished film. However, when Jamie Lee Curtis expressed interest in returning to the series, Kevin Williamson--who was coming off of his blockbuster success with Scream (1996)--was asked by Dimension Films to pen a treatment that added Laurie Strode. When the WGA deemed that Williamson did not deserve writing credit on the screenplay, Dimension Films--hoping to market the film as 'From the creator of Scream'--offered Zappia more money to share the writing credit. Zappia declined, and Williamson only possesses Executive Producer credit on the finished film.

The original treatment for "H20" by Kevin Williamson was much more sparse on character detail and had a radically different ending. In the place of Nancy Stephens' character of Marion Whittington in the trademark "Williamson opener", a new character was originally to be created, "Rachel Loomis", apparently Dr. Sam Loomis' daughter, who would have the computer files on Laurie Strode/Keri Tate on her home computer. Rachel would come home to discover her computer on, and would swiftly be dispatched by the Shape. Also, in the climax of the treatment, there is a massive helicopter and bus chase sequence, culminating in the downed helicopter spinning out of control and decapitating the Shape with its out of control rotor a la Mission: Impossible (1996).

Kevin Williamson was originally hired to write the script and was said to have actually finished a draft or two with the input of Jamie Lee Curtis. Williamson's script was eventually not used, but a treatment he wrote for the movie is said to be a heavy basis for the final, filmed version.

Body Count: 7 (two off-screen)

A subplot involving two Detectives (one male, one female) tracking Michael for the murder of Nurse Stephens was completely cut from the script. Remnants of the characters remain at the start of the picture, when two random detectives are talking in the home office of Stephens's home.

One month after the film was released, Jamie Lee Curtis got a star on the Hollywood Walk of Fame.

P.J. Soles was asked to play the role of Norma Watson. That was also the same name as the character she played in Carrie (1976)

Molly and Sarah are shown watching Scream 2 (1997) when Will the guidance counselor checks in on them, a subtle nod to Scream (1996) when all the teens at the party watch the original Halloween (1978).

The teenagers at the beginning are watching Plan 9 from Outer Space (1959).

In one draft of the script, Charlie was intended to be the killer, acting as Michael Myers copycat killer.

The majority of John Ottman's original score was rejected late in post-production and replaced with Marco Beltrami's scores to Scream (1996), Scream 2 (1997), and Mimic (1997). The producers wanted a darker, more Scream-like score, while Ottman's score wasn't strong enough to fit the bill. Some of what remained of Ottman's score was heavily edited and often was used for scenes for which they were not originally intended. Nonetheless, Ottman's music was later released in its entirety on an album entitled "Portrait of Terror", from Varese Sarabande Records.

Jamie Lee Curtis refers to the film as "Field of Screams". "If you build it, they will come."

Charles S. Dutton originally had a small role in the film as a detective, however his part was removed as script rewrites came in.

Laurie teaches in class Mary Shelley's novel Frankenstein and Molly, one of the students, responds to a question about the book and fate with this: "I think that Victor should have confronted the monster sooner. He's completely responsible for Elizabeth's death. He was so paralyzed by fear that he never did anything. It took death for the guy to get a clue." She goes on to say that Victor finally confronts the monster because he "had reached a point in his life where he had nothing left to lose. I mean, the monster saw to that by killing off everybody that he loved. It was about redemption. It was his fate." This foreshadows the final scenes in the movie where Laurie finally decides to stop running from Michael Myers and confront her monster. After twenty years of living in fear and seeing her loved ones murdered, she had nothing more to lose. It was time to face her fears and end the nightmare.

"Halloween: H20" is the seventh film in the series. H2O is the chemical symbol for water which has a pH balance of 7.0.

When Jimmy's first shown, he's wearing a hockey goalie mask which is undoubtedly a reference to Jason Voorhees, director Steve Miner who also directed Friday the 13th Part 2 (1981) and Friday the 13th Part III (1982) the latter movie in which Jason acquires a hockey goalie mask from one of his victims.

When Keri/Laurie (Jamie Lee Curtis) catches John (Josh Hartnet) and drives him back to school after he sneaks out the song "Mr. Sandman," by the Chordettes is playing on the radio in her car. This is the same song that plays at the beginning of "Halloween II" (1981).

Norma (Janet Leigh) tells Kerri/Laurie that the girls shower is clogged again. This is a reference to Janet's role in Psycho (1960) where she was butchered in the famous shower scene.

Kevin Williamson was involved in various areas of production. Although not directly credited, he provided rewrites in character dialogue, which is seen heavily throughout the teen moments. Miramax/Dimension Films felt his involvement as a co-executive producer merited being credited.

Production designer John Willett used Michael Myers' mask to inspire the sets. Willett wanted the exterior of Hillcrest to be calm, "while inside it's totally crazy, just whacko."

Not counting Rob Zombie's films, this is the third highest grossing film of the series.

Originally, director Steve Miner wanted Jerry Goldsmith to score the film, having already worked with him on Warlock (1989) and Forever Young (1992).

The Shakespeare bust in the background of the classroom scene where Frankenstein is discussed is the exact same design as the one from Batman (1966), used by Batman and Robin to access the bat-cave.

There was a subplot that featured Molly as an "ugly duckling" who was madly in love with John Tate whose name was originally Mitch.

The film takes place from October 29 to October 31, 1998.

Some music from Scream (1996)was added to the chase scenes later on during post-production. Composer John Ottman expressed some displeasure about this action in an interview featured on the Halloween: 25 Years of Terror DVD released in 2006. Ottman's score was supplemented with Marco Beltrami's scores from Scream (1996), Scream 2 (1997), and Mimic (1997) by a team of music editors as well as new cues written by Beltrami during the final days of sound mixing on the film. Bob Weinstein demanded the musical changes after being dissatisfied with Ottman's score.

Jamie Lee Curtis first worked with director Steve Miner on Forever Young (1992).

First film in the series to be released in the summer. Every film since including Rob Zombie's followed this trend.

Josh Hartnett (John) and Jodi Lyn O'Keefe (Sarah) were both born the same year the original Halloween (1978) came out, Joseph Gordon-Levitt (Jimmy) was born when Halloween II (1981) came out and even though it's not connected to Michael Myers, Adam Hann-Byrd (Charlie) was born when Halloween III: Season of the Witch (1982) came out.

No official soundtrack was ever released for the film, but a compilation album by John Ottman was released in the United States and Germany under the Varese Sarabande label and includes the original score by Ottman and numerous other cuts.

Sarah Michelle Gellar can be seen on the TV in the girls bedroom as they watch Scream 2 (1997).

The car that Michael steals from the rest stop area from the mother and daughter is a 1956 International Harvester Travelall.

On one of the newspaper clippings seen during the opening credits, a picture of Dr. Sam Loomis can be seen. The character was featured in the previous Halloween films, and was portrayed by Donald Pleasence.

During the opening credits, there's a yearbook photo with Laurie Strode as part of the "Class of 78", meaning she graduated in 1978. However in the original film, Laurie was in school during the fall of 1978. Although it's not mentioned what grade she was in, she would've been the Class of either 79, 80, or 81.

The car Michael steals at the beginning from Jimmys house is a 1971 Buick Skylark.

Laurie/Keri's car is a 1998 GMC Jimmy SLT [S-15].

Laurie's revolver is a, nickeled Smith & Wesson Model 36.

As well as all previous movies (but Halloween III: Season of the Witch (1982) where he doesn't appears), Michael Myers never talks.

As well as all previous movies (but Halloween III: Season of the Witch (1982) where he doesn't appears), Michael Myers never runs.

Moustapha Akkad (the executive producer) said that the killer in H20 was not actually Michael Myers, but in fact a copycat killer, and that this would be explained in the next Halloween movie. The idea was dropped for Halloween: Resurrection (2002), which explained the reappearance of Michael Myers by revealing that he had traded places with a paramedic at the end of H20, who had then been mistaken for Michael, and was subsequently beheaded by Laurie.

There was at one time a plan for Michael Myers to speak a single line at the end of the movie. He was to have said "Laurie" just before being beheaded by Jamie Lee Curtis. This idea was dropped from the final script.

Both Nancy Stephens and Joseph Gorden Levitt are dead before their names appear in the opening credits.

One of the biggest sources of tension between the filmmakers was the issue of the film's ending. Kevin Williamson's treatment had the Shape being cut in half by a helicopter rotor while early drafts of the script had Laurie stabbing him through the heart with a javelin while he was pinned between the two pieces of a retractable gym floor. Moustapha Akkad wanted the Shape to live at the end so he could produce more Halloween films while Bob Weinstein at Dimension Films wanted the Shape to die. Weinstein instructed screenwriter Robert Zappia to write two endings and send the ending with the Shape surviving to Akkad while they would actually shoot the ending where the Shape died. Zappia refused, much to Weinstein's annoyance. According to Zappia, Kevin Williamson concocted the film's ending where the Shape is "killed," as well as the twist shown in Halloween: Resurrection (2002) where it is revealed that the Shape had switched clothes with a paramedic. This solution managed to appease both parties. According to screenwriter Matt Greenberg, it was Weinstein who suggested that Laurie Strode decapitate the Shape with an ax.

Nurse Marion Chambers Whittington previously survived against Michael in Halloween (1978) when he escaped from Smiths Grove sanitarium by trying to strangle her inside the car, in this she's not so lucky as she gets her throat slashed by Michael with a butcher knife.

Tony says to Marion Chambers regarding her smoking habit "hasn't anyone told you second hand smoke kills" to which she replies "Yeah but they're all dead" foreshadows when Michael kills Jimmy, Tony and Marion.

The original versions of the script differed greatly from the finished film with the character Ronnie written as a woman named Hattie (who was killed) and the character Molly also getting killed by Michael Myers.

Michael killing Will by stabbing him in the back with a butcher knife and lifting him off the ground is strikingly similar to how he killed Nurse Jill in Halloween II (1981), (except Michael stabbed her in the back with a scalpel when he lifted her off the ground) and they're both killed in front of Laurie Strode.

This movie and Halloween: Resurrection (2002) are the only two movies to show Michael not getting shot.

Ronny calls Laurie "psycho" as she drives past him when she comes in through the gate. Jamie Lee Curtis' mother Janet Leigh, who appears as Norma in this, starred in Psycho (1960).

Molly is one of FOUR primary female protagonists to survive against Michael, the other three to live are Laurie Strode, Kara Strode in Halloween 6: The Curse of Michael Myers (1995) , and Sara Moyer in Halloween: Resurrection (2002).