Continuity mistake: In a scene near the end of the movie, George enters the Building and Loan with a Christmas wreath on his arm. On hearing that he has a phone call from his brother Harry, he tosses the wreath on a table and picks up the phone. In the next second, the wreath is back on his arm. (01:17:35)
Continuity mistake: Marlowe sits in front of Joe Brody's apartment building, The Randall Arms. Later as he follows the gunman that shot Brody we see it from inside the car and the registration stickers are different. (00:47:40 - 00:57:20)
Continuity mistake: When Frank, the DA and the policeman are discussing the accident, the policeman notices the electrocuted cat and it is shown next to the ladder. In the subsequent wide shot the cat is lying between the beams of the ladder. (00:42:50 - 00:43:35)
Continuity mistake: Watch Devlin's hands in the cafe in Rio. They open and close between shots.