The Chinatown screenplay is now regarded as being one of the most perfect screenplays and is now a main teaching point in screen writing seminars and classes everywhere.

At one point, Roman Polanski and Jack Nicholson got into such a heated argument that Polanski smashed Nicholson’s portable TV with a mop. Nicholson used the TV to watch L.A. Lakers basketball games and kept stalling shooting.

The scene where Roman Polanski slits Jack Nicholson’s nose was extremely complex to film, and they got so tired of explaining how it was done (by using a specially-constructed knife with a short hinge that would be safe as long as it was handled very carefully) that they began to claim Nicholson’s nose was actually cut.

Jack Nicholson had the name “Jake Gittes” written on the sleeves of the shirts he used in the movie. It was done so Nicholson could get into character more easily.

There were many rumors circulating about Faye Dunaway’s diva-like behavior during the making of the film. One such was that she refused to flush her own toilet and expected her assistants to do it for her.

At the time of filming, Jack Nicholson had just embarked on his longstanding relationship with Anjelica Huston. This made his scenes with her father, John Huston, rather uncomfortable, especially as the only time Anjelica was on set was the day they were filming the scene where Noah Cross interrogates Nicholson’s character with “Mr Gittes…do you sleep with my daughter?”

According to Roman Polanski’s autobiography, he was outraged when he got the first batch of dailies back from the lab; due to the success of The Godfather, producer Robert Evans had ordered the lab to give this movie a reddish look. Polanski demanded that the film be corrected.

Roman Polanski eliminated Jake Gittes’ voiceover narration, which was written in the script, and filmed the movie so that the audience discovered the clues at the same time Gittes did.

Faye Dunaway’s distinctive look was inspired by Roman Polanski’s memories of his mother, who in the pre-WWII era would fashionably wear penciled-on eyebrows, and have her lipstick shaped in the form of a Cupid’s bow.

Cinematographer Stanley Cortez was fired soon after production began because his classical style did not match the naturalistic style Roman Polanski wanted for the film and proved too time consuming. Polanski had to find a replacement in only a few days and chose John A. Alonzo. As David Fincher and Robert Towne describe on their DVD commentary, two scenes shot by Cortez are in the film. The orange grove fight with the farmers (but not the following porch scene with Evelyn) and the drive back to Los Angeles at sunset are Cortez’s work.