- Martin Scorsese wanted to shoot the film in Boston, where the story is set. But due to concerns on setting up production and politics, the producers
chose New York City to double for Boston because of the state's 15% tax credit. The bulk of the movie was shot in New York City while a six week shooting
schedule was split in two for Boston, shooting the first half in June and the second half in August. After the success of this film, Massachusetts created a
25% tax credit for filmmaking.
- As of 2007, this film had the highest grossing box-office opening and the highest total box-office gross in Martin Scorsese's career.
- A possible reason why Leonardo DiCaprio did not receive an Oscar nomination for his performance in this movie was because the Warner Bros. studio
initially did not want to favor DiCaprio over his co-stars and place him in the leading actor category. The studio favored DiCaprio's leading performance
in Blood Diamond (2006) (which eventually got him a nomination). DiCaprio himself refused to campaign against his male co-stars in the supporting actor
category, so Warner bought no supporting actor ads for DiCaprio, and he did not receive a nomination.
- The classroom scene, police academy graduation scene, and shooting range scene (all at the beginning of the film) were actually shot near the end of
production. Historic Ft. Schuyler on the campus of State University of New York's Maritime College was the back drop.
- The film is an American adaptation of the Hong Kong film Mou gaan dou (2002) (Infernal Affairs) directed by Wai-keung Lau and Siu Fai Mak and starring
Andy Lau and Tony Leung Chiu Wai.
- Leonardo DiCaprio was cast in the title role in The Good Shepherd (2006), but he dropped out to play Billy Costigan in this movie. Matt Damon then took
- Mark Wahlberg based his performance on the police officers who'd arrested him about two dozen times in his youth, and the reactions of his parents
who had to come bail him out with their grocery money.
- The comic book that Frank Costello gives young Collin Sullivan in the beginning of the movie is an issue of the "Wolverine" series, which began
- Robert De Niro was offered the role of Queenan, but ultimately did not take it because of his work on The Good Shepherd (2006).
- Body count: 22
- This is the movie with the most uses of the word "%*##" and its derivatives (237) to win the Best Picture Oscar.
- Warner Brothers bought the remake rights to the film for US$1.75 million in 2003.
- When receiving the top award from the Director's Guild of America for this film, Martin Scorsese said that this "is the first movie I have ever
done with a plot."
- Martin Scorsese said that he made this film to honor crime genre directors such as Robert Aldrich, Samuel Fuller and 'Don Siegel (I)'.
- 'RZA' was offered Anthony Anderson's role, but turned it down because of scheduling conflicts.
- Originally, Jack Nicholson turned down his role in the movie, but after a meeting with Martin Scorsese, William Monahan and Leonardo DiCaprio, he was
finally convinced to play the role of Frank Costello. The main reason he joined the production was because he had previously done a few comedies, and wanted
to play a villain again, and he considered the character of Costello to be the ultimate incarnation of evil.
- Many scenes with Jack Nicholson were improvised. Nicholson was given the opportunity to do whatever he wanted to add to the character's
unpredictability. The scene where Billy and Frank are talking was loosely scripted, and many surprises happened in it, including Frank pulling out the gun.
- The rat at the end is completely digital.
- The movie the bank robber is watching before being shot in the knee by Costigan is The Informer (1935).
- The CD that Costigan mails to Colin is mailed in the cover for The Rolling Stones' album "Exile on Main Street". Earlier in the film, when
Costello beats Costigan's hand with his own shoe, a song from the album, "Let it Loose", plays over the scene.
- Ray Liotta was the original choice for the role of Dignam but had to reluctantly decline due to other commitments.
- Denis Leary was offered the role of Dignam in this film, but turned it down due to scheduling conflicts with his television show, "Rescue Me"
- Gerard McSorley was originally slated to play Queenan but had to drop out of the project.
- As research for his character's occupation, Matt Damon worked with a Massachusetts State Police unit out of Boston. He accompanied them on routine
patrols, participated in a drug raid and was taught proper police procedures like how to pat down a suspect.
- Martin Scorsese had originally wanted to cast a known actress, either Kate Winslet or Hilary Swank, for the part of Madolyn. But he later decided to go
with someone new instead (Vera Farmiga).
- Because Martin Scorsese was so pleased with technical advisor Thomas B. Duffy, he let him appear on-screen as the Governor of Massachusetts swearing in
the new Police Academy graduates.
- While shooting on location in Boston, Massachusetts, Martin Scorsese viewed the film's dailies at Emerson College.
- Jack Nicholson refused to wear a Boston Red Sox hat during filming and instead wore his New York Yankees hat.
- Martin Scorsese put the finishing touches on this film a week before its theatrical release.
- Colin Sullivan's (Matt Damon) apartment does not exist. The view of the Massachusetts State House was an effect shot from the roof of Suffolk
University, which is the law school where Sullivan says he is taking night classes. Michael Ballhaus, the film's cinematographer, evaluated the shot
- Originally Brad Pitt was cast as Colin Sullivan, but later dropped out to work with Alejandro González Iñárritu in Babel (2006). He continued to produce
the film under his (and his then wife Jennifer Aniston's) production company, Plan B.
- The newscaster seen reporting the news story detailing the dumped body by Costello's gang was a real Boston area newscaster at the time of filming.
He reported for Boston's Warner Brother's affiliate station WB56.
- When the main characters are shown in a police academy ballistics lecture at the beginning, the large flip chart illustrations seen in the background are
Warren Commission exhibits of President John F. Kennedy's head wounds, prepared by medical illustrator H.A. Rydberg under the direction of Dr. James
Humes, the chief examiner of Kennedy's autopsy.
- After completing The Aviator (2004), Martin Scorsese kept Alec Baldwin in mind for future collaboration and ultimately decided to cast him in the role of
Ellerby which was offered to Mel Gibson first, but Gibson was unable to accept the part because he was starting production on Apocalypto (2006) at the time.
- The scene where Frank Costello throws cocaine on hookers was one of many bizarre ideas contributed by Jack Nicholson, who also suggested wearing a
strap-on for the scene with Matt Damon in the porn theater.
- According to his file, Billy Costigan's birthday is November 7, 1984. Although a second shot of the same screen then labels his date of birth as
November 7, 1980 (See "Goofs" section).
- The movie's title does not appear until almost 18 minutes into the film.
- At the beginning of the film Frank Costello instructs the store clerk to fill a white paper bag with various groceries for the kid Colin Sullivan,
notably a couple of loaves of bread and a couple of quarts of milk. In the last scene of the film we see adult Colin Sullivan walking into his apartment with
a white paper bag full of groceries, two of the items you can see in the bag during this scene are a couple of loaves of bread and a couple of quarts of
- In the dinner scene with Madolyn, Colin states that "what Freud said about the Irish is we're the only people impervious to
psychoanalysis." Despite what you may find on a Google search or the Boston Globe, Freud didn't actually ever say that. In a clever act of
investigative journalism, a man named Dr. Charles wrote to the director of research at the Freud Museum in London, and asked him about the legitimacy of the
quote's attribution. His response (which is also stated on the FAQ section of the museum's Website): "There is no evidence Freud said [the
quote]. The only documentation seems to be Anthony Burgess, in his introduction to a book of Irish short stories: 'One of [Freud's] followers split
up human psychology into two categories - Irish and non-Irish.'"
- Chris Messina met with Scorsese to discuss taking on one of the roles in the film.
- When Queenan and Dignam are interviewing Costigan, Costigan says "Families are always rising and falling in America." Queenan wants to know who
said that, and it turns out to be Hawthorne. Dignam quips, "What's the matter smart ass, don't know any fuckin' Shakespeare?" Later, as
Queenan hands the clipboard to Sullivan, it is Queenan who quotes Shakespeare with "the readiness is all," from Hamlet's "Fall of a
sparrow speech," Act V, scene ii.
- Although Sgt. Dignam's first name is never mentioned in the film, William Monahan has stated that Dignam's full name is Sean Dignam.
- The "MASS Processor Company's" microprocessor shown in the movie is really an ST Microelectronics' ST9F150JDV1QC micro-controller,
released in 2003 and intended for applications such as MP3 players, GPS devices, and car radios. It went for around $7 at the time it was released (in the
movie it is stated they go for $100,000 each). The microprocessor has an internal clock frequency of 24 Megahertz and 100 pins and can address up to 4
Megabytes of memory. A typical Intel Core 2 Duo microprocessor, released in 2006 (the same year as The Departed) for use in desktop computers, runs at 1400
Megahertz or higher frequencies, has 775 pins, and can address up to 4000 Megabytes.
- The film's technical advisor was Thomas B. Duffy, a retired Massachusetts State Police major who worked out of Boston for nearly thirty years and
specialized in organized crime. He was particularly involved in the case against notorious South Boston mob boss James 'Whitey' Bulger, whom Frank
Costello is partly based on. Duffy appears as the Governor who delivers a speech to the graduating police cadets. Bulger, who is still wanted by the FBI, was
spotted coming out of a theater showing the film by police in San Diego, California.
- When Madolyn meets Colin in the elevator, she gives Colin her business card. The logo of the psychological Corporation is clearly visible on it.
- Martin Sheen, who plays Queenan, asks for a light before getting attacked. His son Charlie Sheen does the same in The Rookie (1990).
- Whenever any of the main characters is about to die there is an "X" somewhere on screen as a reference to Scarface (1932).