Thirteen hours after filming April Kepner's birth scene, Sarah Drew (Dr. April Kepner) went into labor.

The character Alex Karev was not in the original pilot script. His role was inserted into the pilot as an afterthought, in order to provide a foil, as well as male companionship for Dr. George O'Malley. Since he wasn't added until after the pilot was shot, scenes with him were either re-shoots or digitally altered.

Every episode shares the name with a song title by a popular artist. Several are named after The Beatles and R.E.M. songs.

Kate Walsh's character, Addison Shepherd, was only supposed to appear in five episodes, but Addison quickly developed a fan base, so they kept Walsh on the show.

Miranda Bailey was the only role written with a character description: "tiny blonde with curls".

Dr. Bailey (Chandra Wilson) and Dr. Meredith Grey (Ellen Pompeo) are the same age in real-life.

Ellen Pompeo has stated in an interview that Shonda Rhimes originally wanted to pair up her character with Isaiah Washington's because she wanted an interracial couple on the show. However, Pompeo preferred Patrick Dempsey, because in real-life, she is in an interracial relationship, and thus being paired up with Washington felt too close to home.

The show's title is a reference to the famous anatomy book "Gray's Anatomy of the Human Body" by Henry Gray.

Patrick Dempsey auditioned for the role of Dr. Gregory House on House (2004), before taking the role of Dr. Shepherd.

T.R. Knight left the show at the end of season five, because he felt that his character, Dr. George O'Malley, wasn't given enough storyline, or on-screen time throughout the season. He said that there was a "breakdown in communication" between him and Creator Shonda Rhimes. Instead of making any demands, he just asked to be written out of the show.

Chyler Leigh (Dr. Lexie Grey) was pregnant with her third child during season five.

The first person to refer to Dr. Shepherd (Patrick Dempsey) as "McDreamy" was Cristina (Sandra Oh).

Shonda Rhimes said on an interview that she had a clear idea for the show's end, but its success kept growing to the point that her ending was no longer proper, so she decided to use the idea on a storyline and come up with another ending.

In an early episode, Meredith is seen posting a poster asking for a roommate. The poster is only visible for a second, but it mentions that "Bush supporters need not apply" along with other details about the house.

As is common for major television and film productions, stars of the show have become famous in roles other than those they originally sought. Sandra Oh was initially looking to audition for the part of Dr. Bailey. On The Oprah Winfrey Show (1986), Isaiah Washington (Dr. Burke) said that he had auditioned to play the role of Dr. Shepherd.

Hilarie Burton (Dr. Lauren Boswell) and Jeffrey Dean Morgan (Denny Duquette) are a real-life couple. They both played parts on this show, but not in the same season.

In order to keep the plot and storylines secret, the main characters' names are changed in auditions.

Katherine Heigl was released from her contract during season six. She appeared in some episodes of the season, and then took time off to be with her family. She was supposed to come back for the season finale, although this never happened, and her last episode was episode twelve, "I Like You So Much Better When You're Naked".

The name "Dr. Mark Sloan" is a reference to Dick Van Dyke's character, by the same name, in the television show Diagnosis Murder (1993).

The first person to refer to Dr. Mark Sloan (Eric Dane) as "McSteamy" was Dr. Meredith Grey (Ellen Pompeo). However, Meredith was not the first character in the show to use the term "McSteamy" in general. Nurse Tyler (Moe Irvin) was the first to say it, instead of "McDreamy", as he most likely misheard.

Sadie and Meredith referred to each other as Die and Death, which is a play on their names, saDIE and mereDEATH.

Rob Lowe was originally considered for the role of Dr. Derek Shepherd, but passed on it.

The show was originally titled "Complications".

Patrick Dempsey and Kevin McKidd were in a love triangle in Made of Honor (2008).

Sandra Oh received critical acclaim for her portrayal of Dr. Cristina Yang, which included a Golden Globe win, a Screen Actor's Guild Award win, and five consecutive Emmy nominations.

Similarities between Katherine Heigl's characters in Roswell (1999) and this show: in each, her character, Isabel/Isobel, has a pivotal scene in a pink, strapless gown, has a love interest named Alex, sees, talks to, and dances with a dead lover.

Katherine Heigl dropped herself out of Emmy consideration in 2008, because she felt that she wasn't given the material that would warrant a nomination.

The producers of this show released a novel in 2006 depicting the lives and happenings of two bit-part characters; Joe the Bartender and Nurse Debbie. The book is double-sided, written in blog and IM form, while gossiping on the actions of the Grey's characters. The events discussed, give background information for Joe and Debbie, and give insight on the events and cases, with which the doctors deal on the show.

The name of Joe's bar is "The Emerald City Bar".

Dr. Alex Karev (Justin Chambers) was the first person to refer to Dr. George O'Malley (T.R. Knight) as "007".

An article in a 2014 issue of the scholarly journal Communication Research reported on the results of several studies that all found that being a regular viewer of this show correlated with having much more strongly negative attitudes toward organ donation than non-viewers. The article said, in part: "Of the medical dramas examined for depicting organ donation myths, perhaps no program features as many inaccuracies as Grey's Anatomy (2005) (see Morgan et al., 2007; Morgan et al., 2010; Morgan, Movius, and Cody, 2009; Quick, 2009). Unfortunately, the impact of these inaccurate media portrayals results in misguided societal beliefs about organ donation (Morgan et al., 2010) and often surface as reasons for declining to register to be organ donors (Morgan et al., 2005)."

T.R. Knight was asked to appear in flashback scenes during season six, but he refused, preferring to pursue other projects.

As of 2016, this is the last broadcast network television series to win the Golden Globe for Best Television Series Drama.

Ellen Pompeo grew up in Boston, just like her character, Dr. Meredith Grey.

Taylor Swift is a big fan of the show. She even named one of her cats Meredith Grey, after the main character.

Dr. Cristina Yang is an M.D. and PhD. Her PhD is in biochemistry.

Kevin McKidd (Dr. Owen Hunt) and Jessica Capshaw (Dr. Arizona Robbins) share the same birthday, August 9, but are three years apart.

The Inuit doll that frequently appeared in episodes, is named Ipecac. Ipecac is featured in an Easter Egg in the Season One DVD Bonus Features, where the cast and crew discuss the doll, its name, origins, and a plot to kidnap it.

Jeff Perry and Laurie Metcalfe, who were married and are now divorced, guest starred on season two, episode twenty-two, "The Name of the Game", without sharing any scenes.

Dr. Meredith Grey lives on 613 Harper Lane.

Derek talks about his love of ferry boats. On his cap he always wears in surgery, it has ferry boats on it.

Many actors and actresses that have appeared on this show have gone on to play roles in Scandal (2012), one of Shonda Rhimes' other shows. They include Scott Foley (Henry Burton), Kate Burton (Dr. Ellis Grey), Jeff Perry (Thatcher Grey), Robert Baker (Dr. Charles Percy), and Amanda Fuller (Dr. Morgan Peterson). Also, Kelly McCreary (Dr. Maggie Pierce) appeared on two episodes of Scandal (2012) before appearing on this show. Bellamy Young, (Mellie Grant on Scandal (2012)), season three episode twenty-three of this show, Katie Lowes (Quinn Perkins on Scandal (2012), on season seven of this show, briefly as an operating room patient). Finally, Valerie Cruz guest appeared on both shows.

Cristina attended Stanford University, and graduated first in her class.

Dr. Derek Shepherd (Patrick Dempsey) and Dr. Lizzie Shepherd (Neve Campbell) appeared in Scream 3 (2000).

Karev's full name is Alexander Michael Karev.

This is the first ABC primetime drama series to reach its 300th episode. The only ABC primetime scripted series to have a longer run is the sitcom The Adventures of Ozzie and Harriet (1952), which ran for 435 episodes.

Richard and Adele had their first dance to the song "Funny Valentine". Loretta Devine (Adele Webber) appeared in Funny Valentines (1999).

Meredith went to Dartmouth College.

Lexie's full name is Alexandra Caroline Grey.

In the first episode featuring Dr. Arizona Robbins, she and Dr. Alex Karev get on a plane to harvest organs. Arizona says that she hates flying, because it makes her feel closer to death.

Jessica Capshaw (Dr. Arizona Robbins) at the beginning wanted her character's love interest to be Justin Chambers (Dr. Alex Karev).

Dr. Callie Torres (Sara Ramirez) often seems to have a type, such as blonde and blue-eyed. For example: Dr. Erica Hahn (Brooke Smith) and Dr. Arizona Robbins (Jessica Capshaw) (season five).

Izzie's full name is Isobel Katherine Stevens.

All of the original series cast (excluding Justin Chambers and James Pickens, Jr.) received at least one nomination for a major award. Most of them even won their category, including Chandra Wilson (SAG), Sandra Oh (SAG, Golden Globe), and Katherine Heigl (Emmy).

The ferry boat scrub cap Derek always wore and later on by Meredith is actually boats like ocean liners or tug boats not ferry boats.

Derek's full name is Derek Christopher Shepherd.

Cristina's stepfather is Jewish.

Patrick Dempsey (Dr. Derek Shepherd), Eric Dane (Dr. Mark Sloan), and Hector Elizondo (Carlos Torres) appeared in Valentine's Day (2010).

Marika Domininczyk , who plays Eliza Minnick, is married to Scott Foley, Henry Burton.

My So-Called Life (1994), whose protagonist was named Angela Chase, was an ABC show, just like this show. Three of the stars of My So-Called Life (1994) have made memorable appearances on this show: Wilson Cruz played a gay teen, who was one of Angela's best friends, Ricky Vasquez made a guest appearance as Kyle, a gay man in 2011; Tom Irwin, who starred as Angela's father, Graham Chase, appeared three times as Police Commander Marty Hancock, who assisted Seattle Grace during one of its most crucial crises in 2010 and 2011; and, Jeff Perry, who played Angela's teacher, Richard Katimski, was featured as Thatcher Grey, the father of Meredith, from 2006 to 2011.

Kate Walsh (Addison Mongomery) and Caterina Scorsone (Amelia Shepherd) have been main characters on both Grey's Anatomy and its spin-off, Private Practice (2007).

Justin Chambers (Dr. Alex Karev) and Rachael Taylor (Dr. Lucy Fields) share the same birthday, July 11, but are fourteen years apart.

Scott Foley, Neve Campbell, and Patrick Dempsey appeared in Scream 3 (2000).

Alex was the first person to say Seattle Grace Mercy Death. Christina was the second to coin the phrase.

George O'Malley was referred to as "Bambi".

The most viewed episode of the series too date remains "It's the End Of The World" (2006) with over 37 million viewers tuning in.

Many scenes show early morning coffee on the terrace, standing in front of the hospital contemplating entrance, sun coming up as the night shift leaves and it's perfectly rising above the ocean. and so forth. But in actuality, the sun would be setting into the ocean not vice versa.

Jana Kramer, Bethany Joy Lenz, and Hilarie Burton appeared on One Tree Hill (2003).

Hector Elizondo's character, Carlos Torres was cast as "Mr. Grey" in the 1974 version of The Taking of Pelham One Two Three (1974).

Eric Dane (Dr. Mark Sloan) decided to leave the show. Shonda had a hard time deciding what to do with his character, so she decided the best option was for him to die. In an interview, she had stated that she did not want Mark to be mourning the loss of Lexie, and that they're still together somehow.

Chyler Leigh (Dr. Lexie Grey) decided to leave the show in order to spend time with her three children.

Meredith's dreams in the first episode of season five can be considered a foreshadowing of Derek's death in season eleven, since both events involve Derek's car being rammed by a much larger vehicle (a bus in season five, and a truck in season eleven). Also, when Meredith creates a giant blueprint of candles on Derek's land, he says "Stay here. Wait for me". These words are also the last words he told Meredith before leaving for a flight to Washington, D.C.

All of the original interns (Meredith Grey, Cristina Yang, Alex Karev, George O'Malley, and Isobel Stevens) have had surgery at some point in the series. Meredith for liver donation to her father, an appendectomy, the surgeries to save her life after being attacked by a patient, and a c-section, Christina for an ectopic pregnancy, Alex for the gunshot, George after he got hit by a bus, and Isobel for her cancer, as well as a transplant surgery for her daughter's cancer.

Ellen Pompeo, Justin Chambers, Chandra Wilson, and James Pickens, Jr. are the only cast members still on the show, who were in the first season.

In season six, episodes twenty-three and twenty-four, "Sanctuary", and "Death and All His Friends", when Meredith tells Cristina she is going to be a godmother, Cristina says if they get into a plane crash, she will keep the child, and at the end of season eight, Meredith, Derek, and Christina were all in a plane crash.

Most of the main female characters have been pregnant (Meredith, Cristina, Callie, April, Bailey, and Amelia).

Dr. Jo Wilson's real name is revealed to be Brooke Stadler.

Sarah Drew and Jesse Williams knew that Jackson was going to interrupt April's wedding to Matthew when they began filming season ten, so when they read it, in the table read for season ten, episode twelve, they weren't that shocked.