Trivia: In the scene where Doctor Spivey is interviewing McMurphy, this whole scene is improvised. Spivey (Dr. Dean Brooks) is the ACTUAL doctor of the institute in real life, and was simply told to interview Jack Nicholson (McMurphy) as if he was a real patient. Nicholson had to improvise and get from the beginning of the scene to the end.
Trivia: The Hindenburg explosion and fire towards the end of the movie combines filmed footage with actual newsreel footage of the disaster.
Trivia: Science-fiction author Harlan Ellison wrote the original novella "A Boy and His Dog" in 1969, and director L.Q. Jones wanted Ellison to also write the screenplay for this 1975 film. When it became apparent that Ellison could not provide a screenplay (due to "writer's block"), Jones co-wrote the screenplay. In a DVD commentary decades later, Jones said that Ellison was pleased with the finished screenplay and movie except for certain dialogue. Ellison was especially offended by the last line of the movie, spoken by the telepathic dog, Blood: "Well, I'd say she certainly had marvelous judgment, Albert, if not particularly good taste." (This grisly line alluded to Vic and Blood eating Quilla June Holmes, the female love interest, in an act that happens off-camera.) Harlan Ellison said it was a "moronic, hateful, chauvinist last line, which I despise."
Trivia: Lina Wertmuller became the first woman to be nominated for an Academy Award for Best Director with this film.