Continuity: When Marlowe goes to Geiger's house, in the foreground is the house's mailbox with "AG Geiger 460" visible on it. When Marlowe later calls his pal Bernie at the D.A.'s office, he gives the address as "7244 Laverne Terrace".
Revealing mistakes: General Strenwood says his legs are paralyzed, though his legs are seen moving under the blanket at the beginning of the movie.
Continuity: When Marlowe returns to his apartment after taking Carmen home from Geiger's house, there is a tight shot of his (Marlowe's) front door, on which there is a bracket holding a card that reads "Philip Marlowe - Private Investigator" and "206" in large numbers. When he opens the door to the apartment and the shot changes to a wide one, the number has disappeared.
Audio/visual unsynchronized: When Vivian is telling Marlowe the cover story for Carmen for the night before, her mouth does not match what she's saying. This mismatch is because the movie was re-edited after Humphrey Bogart and Lauren Bacall became a popular team; To Have and Have Not (1944) which brought them to stardom was released after The Big Sleep (1946) was filmed but before it was released. Scenes were re-shot, some new scenes were added and others dropped. The sequence was also changed to accommodate some of the new edits. The audio/visual mismatch is because the scene was kept but minor dialog had to be changed to make the re-sequencing track properly.
Continuity: The size of Vivian's glass and the amount of liquid in it doubles from when she walks to the bedroom window and sets the glass on the window sill.
Continuity: Marlowe keeps 2 guns in his car - under the dash. One's a snub-nose revolver and the other has about a six inch barrel. He uses and loses the snub-nose. Later, at Art's garage, he reaches in and grabs the larger gun. But in the exterior scenes following, he's got the snub-nose in his hand.
Continuity: The guns hidden in Marlowe's car: first he chooses the one on the left and later when he shoots Canino he picks the same gun, but the other is missing.
Continuity: When Bogart is in the house with the beaded curtain, the curtain is always completely still even after a very short time of passing through it. The first time Bogart goes into the bedroom and out again, you can see the curtain continue to move for a certain duration. His movements past the curtain should have them moving each time he comes back out of the bedroom because that duration is less than the first time.
Factual errors: The business card for Geiger's bookshop, seen in a closeup insert, places it on "S. Sunset," yet Sunset Boulevard in Los Angeles actually runs East and West.
Continuity: When the station wagon pulls out of the alley behind Giegers book store, the crates extend past the car body and are on the tail gate. When the station wagon pulls up to the Randall Arms and pulls into the alley, the crates are now fully inside the body of the car.
Continuity: When Mr. White asked Marlowe, "your willing to lose your license for the case" Marlowe responds by looking directly at him, but when Mr. White asked him another question, the camera immediately cuts to Marlowe looking the other way (as if he never looked at Mr. White in the first time).