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.
Shonda Rhimes said on an interview that she had a clear idea thought for the show's end, but its success kept growing to the point of her ending no longer being proper, so she decided to use the idea on a storyline and come up with another ending.
As is common for major TV 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.
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.
Original cast-member Katherine Heigl was released from her contract during season 6. She appeared in some episodes of the season and then took some time off to spend time with her family. She was supposed to come back for the season's finale, though. This never happened and her last episode as cast-member was Grey's Anatomy: I Like You So Much Better When You're Naked (2010).
Similarities between Katherine Heigl's characters in Roswell (1999) and Grey's Anatomy (2005): 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, and is extremely fussy about the holidays.
The producers of Grey's Anatomy (2005) 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 themselves and give insight on the events and cases the doctors deal with in the show.
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 Grey's Anatomy (2005) 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, & 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)."
Fisher Plaza, which houses Seattle's ABC affiliate KOMO-TV, is used for some exterior shots of Seattle Grace Hospital. In the pilot episode when the patient is flown in via helicopter, you can see the KOMO 4 logo on the side of the building and their 10+ satellite dishes on the roof. Fisher Plaza puts Seattle Grace conveniently close to the Space Needle, the Seattle Monorail, and other local landmarks. However, the hospital used for most other exterior and many interior shots is not in Seattle; these scenes are shot at the VA Sepulveda Ambulatory Care Center in North Hills, California.
The Inuit doll that frequently appears 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.
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.
My So-Called Life (1994), whose protagonist was named Angela Chase, was an ABC show, just as Grey's Anatomy (2005) is. Three of the stars of My So-Called Life (1994) have made memorable appearances on Grey's Anatomy (2005): Wilson Cruz, who 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 3 times as police commander Marty Hancock who assisted Seattle Grace during one of its most crucial crises in 2010/11; and, Jeff Perry, who played Angela's teacher, Richard Katimski, was featured as Thatcher Grey, the father of Meredith, from 2006-2011.
Eric Dane (Dr. Mark Sloan) decided to leave the show since he got a role on The Last Ship (2014). Shonda Rhimes 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.
Meredith's dreams in the first episode of season 5 can be considered a foreshadowing of Derek's death in season 11, since both events involve Derek's car being rammed by a much larger vehicle (a bus in season 5 and a truck in season 11).
T.R. Knight left the show at the end of season 5, because he felt that his character 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.
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, 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.
Sarah Drew and Jesse Williams knew that Jackson was going to interrupt April's wedding to Matthew when they began filming season 10, so when they read it in the table read for season 10 episode 12, they weren't that shocked.
In the hospital shooting episode when Meredith tells Christina she is going to be a god mother Christina says if they get into a plane crash she will keep the child, and in Season 9 Meredith, Derek and herself are all in a plane crash.