The title is an anagram of "truths and lies", and "truths/denials".

Mark Ruffalo won the role of Chuck Aule after sending Martin Scorsese a fan letter saying how much he wanted to work with him.

Before Martin Scorsese and Leonardo DiCaprio decided to make this movie, they were originally going to make The Wolf of Wall Street (2013). However, financing did not work out for The Wolf of Wall Street (2013) at that time.

The movie's $40.2 million opening weekend take in the U.S. marked a career best for Martin Scorsese. It went on to gross over $293 million worldwide, making it the highest grossing movie of his career. This was later surpassed by The Wolf of Wall Street (2013).

The quote "Remember us, for we too have lived, loved and laughed", seen on a plaque on the way to the mental institution, is taken from Medfield's Vine Lake Cemetery. A contest was held to come up with a quote to be used on a stone marker as a remembrance of those who died in the 1918 influenza epidemic known as the Spanish flu.

The only movie of the partnership between Martin Scorsese and Leonardo DiCaprio that failed to receive any Oscar nominations. Gangs of New York (2002), The Aviator (2004), The Departed (2006), and The Wolf of Wall Street (2013) all received Oscar nominations, including for Best Picture.

The working title for this movie was "Ashecliff", the name of the insane asylum.

As of 2013, this is the last Martin Scorsese movie to be shot entirely on film.

To give his cast members an idea of how this movie would be stylistically, Martin Scorsese screened Out of the Past (1947) and Vertigo (1958) for his cast and crew.

Based on the book "Shutter Island" by Dennis Lehane. The book was released in 2003.

Filmed in four months during 2008.

David Fincher was considered as a director.

The ballpoint pen Teddy (Leonardo DiCaprio) used in the movie is a Parker Jotter, it was released in 1954 (the year this movie takes place), and was the first successful and reliable ballpoint pen to hit the market, which quickly drove fountain pens into obsolescence. Over three and a half million pens were sold that year, and the Parker Jotter dominated the ballpoint pen market during that decade.

The whispered line in Complex C ("Stop me before I kill more") is likely a reference to William Heirens, a serial killer in Chicago in the 1940s.

First scheduled to be released by Paramount Pictures in the U.S. and Canada on October 2, 2009, to be in contention for that year's Oscars. Paramount Pictures later pushed this movie back to February 19, 2010, due to financing problems (the studio didn't have the fifty to sixty million dollars necessary to promote an awards movie). Another reason cited for the pushback was Leonardo DiCaprio's unavailability for the interview circuit due to other filming commitments. Paramount Pictures also figured that a movie geared towards adult audiences might achieve some traction in the doldrums month of February, when there are traditionally very few "intelligent" movies released.

Scenery from Peddocks Island (initial island approach), Peddocks Island in the Boston Harbor, Massachusetts, Acadia National Park in Maine, Medfield State Hospital in Medfield, Massachusetts, and the Rice Estate at Turner Hill Country Club in Ipswich, Massachusetts, were combined via CGI to create the imagery of Shutter Island as a whole. The large mountainous area of the island, seen during the ferry approach, was added in post-production, and does not exist, but the decaying brick buildings on the lowlands are real ruins from Peddocks Island.

Shortly before its original release in October 2009, the movie was pushed back to February 2010. It did, however, have a special "secret" screening at Austin's "Butt-Numbathon" film festival in December of 2009. Critics attended the screening, but were asked not to release their reviews until the official release date.

This is the fourth time that Martin Scorsese and Leonardo DiCaprio have worked on a movie together. They previously collaborated in Gangs of New York (2002), The Aviator (2004), and The Departed (2006).

Before settling on Mark Ruffalo for the role of Chuck Aule, Leonardo DiCaprio and Martin Scorsese also considered Robert Downey, Jr. and Josh Brolin. All three are part of Marvel's Cinematic Universe, as Bruce Banner, a.k.a. The Incredible Hulk, Tony Stark, a.k.a. Iron Man, and Thanos respectively. Sir Ben Kingsley also appeared in the Marvel Cinematic Universe as the Mandarin in Iron Man 3 (2013).

The cast includes two Oscar winners: Sir Ben Kingsley and Leonardo DiCaprio; and five Oscar nominees: Max von Sydow, Mark Ruffalo, Michelle Williams, Jackie Earle Haley, and Patricia Clarkson.

Columbia Pictures first optioned the movie rights to Dennis Lehane's novel in 2003 when it was first published. But after many delays, the rights relapsed back to the author.

The film was intended to be released in October 2009, but it was postponed, because Paramount Pictures' remaining yearly marketing, and Oscars campaigning budget, could only afford for its two other movies, Up in the Air (2009), and The Lovely Bones (2009).

Some of Val Lewton's 1940s zombies movies were an inspiration for Martin Scorsese in creating this movie's mood.

This movie opened with a forty-one million dollar weekend, Martin Scorsese's best figures, and (up until the release of Inception (2010) later that same year) Leonardo DiCaprio's.

This was originally commissioned as a directing vehicle for Wolfgang Petersen. However, there were considerable modifications made to Dennis Lehane's novel in order to create a more action-driven blockbuster.

Sir Ben Kingsley also starred as a doctor of an insane asylum in Stonehearst Asylum (2014).

This movie takes place in 1954.

Leonardo DiCaprio and Michelle Williams appeared in Lassie productions. DiCaprio appeared in two episodes of The New Lassie (1989), when he was fifteen-years-old, and Williams made her theatrical movie debut in Lassie (1994), when she was thirteen.

Leonardo DiCaprio's character mentions filing papers with "Hoover's Boys" during his first meeting with Dr. Cawley and Dr. Nahring. Leo played J. Edgar Hoover in Clint Eastwood's J. Edgar (2011).

Michelle Williams and Patricia Clarkson appeared in The Station Agent (2003).

The actual island is linked to Batman in which Gotham has an island called Arkham asylum which is for mentally unstable patients and dangerous prisoners. In the movie, they mention the island is covered in Poison Ivy, which also could be linked to one of Batman's villans who resembles the same name. She also appears as one of the main villians in the Batman: Arkham Asylum video game which is based of the island asylum

There are several clues and intentional continuity errors throughout the movie that foreshadow the ending. This includes a patient's drink of water disappearing between shots (she drinks from an empty hand), a cardigan appearing briefly on Rachel (which is later worn by the other Rachel), and lines from Edward's, a.k.a. Andrew's dreams being repeated (such as "Why are you wet, baby?"). These techniques are also used in his dreams, showing a similarity between what he perceives as a dream, and what he perceives as real.

Leonardo DiCaprio's character has so polarized his two personalities that, for the first part of the movie, Teddy never strikes a match to light his own cigarettes. This is no doubt because he associates matches with arson, and the elusive Andrew Laeddis. However, as Ashecliffe's treatment begins to merge his personalities, he begins striking his own matches, particularly when he traverses cell block C.

The traumatic killing of Nazi guards of Dachau concentration camp is a historical event, taking place on April 29, 1945, when the camp was liberated by the U.S. Army.

Even though Auschwitz is the most commonly known concentration and death camp to have the iron gates with "Arbeit macht frei" ("Work sets you free"), it was not the only camp to have this inscription whether on a gate or elsewhere. Dachau did have the iconic gate as well, so it is correct that Teddy would have seen this gate, and the gate would be in the scenes of them liberating the camp.

Teddy Daniels' final line to Chuck Aule ("This place makes me wonder," he asks, "which would be worse, to live as a monster, or to die as a good man") is not in Dennis Lehane's book, and inspired an article in The Guardian (U.K.) over what this movie's ending really meant. While Leonardo DiCaprio and Martin Scorsese did not have concrete answers, Psychiatric Advisor, Dr. James Gilligan, said that Daniels did choose his fate (and chose it as Andrew Laeddis). Dr. Gilligan said that Daniels' guilt over his past actions, especially his role in causing his wife to lose her mind, and murder their children before he killed her, led him to commit a form of suicide by giving the Shutter Island staff the greenlight to fully lobotomize him. Dr. Gilligan also said that this movie's treatment of Daniels succeeded, because he did face his delusions, but failed in that his (apparently fake) retained psychosis gave the pro-lobotomy individuals a "win" in the debate over their methods versus new, non-surgical treatments.

The Dachau dream sequences were originally intended to be shot entirely in 65mm, but on the second night of using the 65mm cameras, they broke down entirely. However, a few shots in which Teddy goes through the camp in civilian clothes survive in the movie.

Dolores, in the dream sequence, is depicted as having her back hollowed out and ashen. In this aspect, she bears a strange resemblance to the Skogsrå, or Huldra, of Scandinavian folklore: beautiful forest trolls whose backs resembled hollowed-out trunks that seduced men into marrying them. If their men abused them, they would wreak vengeance on the men, or revert to an ugly form. This may connect Dolores' mental breakdown to Teddy's, a.k.a. Andrew's, alcoholism and the implied mental and verbal abuse that she suffered at his hands as a result.

This is one of the rare genre of movies that plays out as a completely different story after the initial viewing reveals a radical plot twist.