Continuity mistake: As Mona Mars and Marlowe talk about Eddie Mars on the left behind him, Marlowe's coat is draped over the couch. If you look closely only his coat is on the couch, but later when Mona storms out, a hat appears on top of the coat. At the end of this scene, the coat is knocked off the back of the couch and appears in a pile with the hat above. (01:37:25 - 01:40:25)????
Continuity mistake: After his car pulls up, Canino gets out and lights up a cigarette that he quickly throws to the ground when Lauren Bacal screams. Later, when Art Huck runs away after Marlowe shoots, we see that same spot again and the cigarette is now bent in half and in a different spot, almost under the car. (01:41:30)????
Continuity mistake: After Canino knocks him out, Mona Mars is there with a glass of water when Marlowe wakes up. If you look behind them on the table to the right of the lamp, there's a small cardholder. No one goes near it but several shots later when Lauren Bacal walks over to sit with them, the card holder moves about a foot to the right. (01:36:55)????
Continuity mistake: Mona Mars throws water in Marlowe's face and as she leaves, we see three pillows propped up against the far wall in the back of the room. Later Marlowe gets up as Canino's car pulls in, and even though no one has gone near them the pillows have been rearranged. (01:39:05 - 01:40:55)????
Continuity mistake: Lauren Bacall takes Marlowe's handkerchief out of his jacket pocket and she begins to wipe off the water that Mona Mars threw in his face. He stops her and says, "Never mind, Angel, the water feels good". She puts the handkerchief back in his pocket, but two shots later it's not there. Then at the end of the scene, it reappears again. (01:39:15)????