Trivia: Willem Dafoe was asked to play Donald Kimball in 3 different ways: he thought Bateman was guilty, he didn't think Bateman was guilty, and he wasn't sure if Bateman was guilty. They were all blended together to make the audience not know what Kimball thought of Patrick Bateman.
Trivia: In the film's original cut, the Grave Robber was in more sequences directly interacting with Shilo. During editing, in order to get the film to a shorter running length, several of his scenes were cut, and he became more of a narrator than a featured character.
Trivia: Part of the film was actually shot at the infamous Cabrini-Green housing projects. The crew had to pay off members of local street-gangs in order to maintain a peaceful shoot. (Although allegedly, one bullet was fired at a production vehicle during photography).
Trivia: In the scene where Regan's mother is supernaturally blasted away from the bedside, she is being yanked by the crew by a length of rope. After dozens of takes director William Friedkin was still unhappy with the look of the shot and ordered the crew to haul her more fiercely. The scream in the shot that made the cut was of genuine pain and required no dubbing for effect.
Trivia: There are lots of signs showing how Evan will die: the doll in the hallway is missing its right eye, the fridge magnets spell 'eye' after one falls off and lastly he has just bought an 'i' Mac computer.
Trivia: The boardwalk scenes were filmed on location at the Santa Cruz Beach Boardwalk in Santa Cruz, California.
Trivia: In the scene where Alice finds Bill's body hanging on the back of the door to the generator room, the producers purposely did not tell Adrianne King what they were going to do to the body nor did they let her see the body beforehand. When she saw the body during filming it was for the first time. The scream she produced was genuine as it scared her badly. Needless to say, that entire scene was shot in one take.
Trivia: Smith tries to explain to the woman who Bob Marley is by singing a part of the song "I Shot the Sheriff." He also sang this part of the song (with a similar voice imitation) in his role as Will in one of the episodes from the series "Fresh Prince of Bel Air".
Trivia: During filming, Val Kilmer became so difficult to work with, that after his final scene was filmed, director John Frankenheimer ordered his crew to "get that bastard off my set."
Trivia: During the feast in which Christian finds a pubic hair inside of his food, look closely at the drinks on the table. While the camera never calls direct attention to this, if you look closely, Christian's drink is very slightly darker than everyone else's. Earlier in the film, the camera briefly passes over a mural that depicts a woman collecting menstrual blood in a cup. (Along with the image of a woman cutting off pubic hairs, like the one Christian found in his food.) It seems Christian's drink has been laced with something he didn't expect.
Trivia: When the movie played in theaters, there was a scene where Dr. Catheter begins to tell Billy about the gremlins before the movie is interrupted by gremlins until they are threatened by Hulk Hogan. When the movie was released on VHS, the scene was changed to static appearing and gremlins constantly changing the channels. This caused many people who bought or rented the movie to think there was something wrong with the tape and took it back to the stores they purchased it from.
Trivia: In Curt Siodmak's original script for the film, whether or not Lawrence Talbot really underwent a physical transformation to a werewolf or if the transformation simply occurred in his mind was left ambiguous. The Wolf Man was never to appear onscreen.
Trivia: When Shaun is on the phone to his mum, Ed shouts "We're coming to get you Barbra". This is a tribute to the famous "they're coming to get you Barbra" line from Night of the Living Dead (1968).
Trivia: The Terror Incognita roller coaster is actually The Hulk roller coaster in Universal Studios, Orlando.
Trivia: Ash's car has appeared in most of Sam Raimi's movies. Look out for it in Spider-Man and Darkman.