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: Author and writer of the book and script William Peter Blatty has a cameo early in this film. He plays the producer trying to have a word with director Burke Dennings on the movie set before Burke turns his attention to Chris MacNeil. William Peter Blatty is the middle eastern-looking guy with the black hair and moustache, which is natural since his mother is originally from Lebanon.Allister Cooper, 2011
Trivia: For the scene in which Father Dyer rushes to give last rites to Father Karras before his death, actor William O'Malley (who played Dyer) was not conveying the urgency, anxiety and grief that director William Friedkin wanted for the scene. According to O'Malley, William Friedkin grabbed O'Malley by the shoulders, screamed and cursed in his face and slapped him before rolling the camera. Thus, O'Malley was authentically shaken up, trembling and on the verge of sobbing in that scene.Charles Austin Miller
Trivia: When Regan vomits on Father Karras, Jason Miller was informed that the vomit would land on his chest. However, director William Friedkin intended the vomit to land in his face so that Miller's reaction would be more genuine. Miller was absolutely furious after this scene and stormed off the set.
Trivia: While rumors of many deaths and strange events surrounding The Exorcist's production were largely fabricated and/or sensationalized for publicity purposes, two of the film's actors did in fact die before the movie was released. The character of Burke Dennings was killed in the film, and the actor who played him, Jack MacGowran, died of influenza shortly after completing his role. Likewise, the character of Mary Karras (elderly mother of Fr. Damien Karras) died in the film, and the actress who portrayed her, Vasiliki Maliaros, also died of natural causes shortly after completing her role.Charles Austin Miller
Trivia: Actress Eileen Dietz doubled for Linda Blair in many of the film's possession sequences, including the infamous projectile-vomiting scene. Dietz, however, received no screen credit for her work, and she later unsuccessfully sued Warner Brothers and the film makers for puking credits.Charles Austin Miller