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: Outside Geiger's house, Marlowe throws his gun down on the floor making Carol Lundgren reach for it. He kicks him and knocks him out but if you look closely he only touches Lundgren's left shoulder with his foot, nowhere near his head. He doesn't hit anything as he falls either. (00:58:55)????
Continuity mistake: Eddie Mars is twirling the key to Geiger's house around his right index finger, but when Marlowe says, "Oh, that's too bad, you got a better one?" and we see him from a different angle he's not doing it. Then in the next shot before he finds the blood stain on the carpet, he's doing again. (00:43:25)????
Continuity mistake: When Marlowe pulls his car up in front of the Randall Arms Apartments and waits for Lauren Bacall his windshield has two stickers on the left of it. A few shots later after Lauren pulls up he gets out and follows her into the building. The car he's sitting in has changed as we see the shadow of the windshield on the front seat and there are now three stickers on this windshield. (00:47:15)????