Continuity mistake: At Spade's apartment, Brigid O'Shaughnessy tells Joel Cairo, "I haven't got the falcon, I'll have it in another week at most, though". The lamp on the table of the right of the screen changes position throughout the scene without anyone going near it. At first it's pointing downward then later it's pointing sideways at the three of them. (00:35:35)
Continuity mistake: Spade tells Joel Cairo, "When you're slapped you'll take it and like it" just before he pummels him. At first there's no blood on his cheek but then in the next shot blood spatter appears out of nowhere. (00:36:40)
Continuity mistake: At Spade's apartment, Brigid O'Shaughnessy and Joel Cairo get into a fight just as Detectives Dundy and Polhaus are talking to him at the front door. They come in and Joel has blood on his face, but it changes between shots throughout the scene. (00:39:10)
Continuity mistake: When Joel Cairo returns to his hotel after being interrogated by the police he asks for the key to Room 603 - but earlier he has told Spade that he lived at Room 635. (00:44:30)
Continuity mistake: Spade walks into his office and Effie tells him that Kasper Gutman called and that Brigid O'Shaughnessy is in his private office. When he first walks in there's nothing by the water cooler on their left but several shots later he walks out to talk to Effie again and now there's a coat rack with several coats on it moved up next to the water cooler. (00:47:25)
Continuity mistake: Spade goes up to Kasper Gutman's hotel room, gets mad and storms out. Before he leaves, everything on the liquor tray on the table in front of them moves between shots. (00:54:25)
Visible crew/equipment: Before Spade walks into Kasper Gutman's hotel room there's one chair against the far wall. When he leaves the room there are two. (00:54:55)
Visible crew/equipment: As Wilmer Cook walks Spade up to Kasper Gutman's hotel room a boom mike shadow appears on Cook before they enter the room. (00:56:55)
Visible crew/equipment: As Spade gives the guns back to Wilmer Cook in Kasper Gutman's hotel room an equipment shadow appears on Cook as they proceed to the couch. (00:57:45)
Continuity mistake: In his hotel room as they speak about the black bird, Kasper Gutman pours Spade a drink. A second glass appears on the table just before they sit down. (00:58:10)
Continuity mistake: The pillow on the hotel room couch moves between shots as Gutman pours Spade a drink. (00:58:10)
Continuity mistake: As Kasper Gutman yammers on about the Maltese Falcon, we see Spade finish his drink. He never goes near the bottle but two shots later there's a small amount of liquid back in his glass. In the next shot it's empty again. (00:59:35)
Continuity mistake: As Kasper Gutman talks to Spade about the Maltese Falcon, we see the bottle of liquor on the table go from half full to three quarters full in two shots without anyone going near it. (01:00:10)
Continuity mistake: Kasper Gutman drugs Spade and as they get up from the couch after speaking about the black bird we see a vase on table with roses in it. The roses have been rearranged and the items on top of the table have moved throughout the scene even though no one has gone near it. (01:03:20)
Continuity mistake: At the end of the movie everyone meets up at Spade's apartment. When he walks in he throws his hat down on the table with the phone on it in front of the window. The next time we see it up close the hat is reversed, everything on the table has been rearranged and his alarm clock appears next to the phone. Later the hat moves without anyone going near it. (01:13:50 - 01:15:50)
Continuity mistake: Kasper Gutman says, "Come come, Mr. Spade. You can't expect us to believe at this late date that you're the least bit afraid of the police" with his left hand on his chin. In the next shot his left hand is at his side. (01:14:05)
Continuity mistake: At the end of the movie Kasper Gutman's bowler is sitting flush on the table to left of him. No one goes near it but later in a close-up it rests at an angle on top of some other clothing. (01:19:20)
Continuity mistake: Spade and Kasper Gutman talk face to face about who killed Thursby and Capt. Jacobi. If you look closely the lamp between them, which has two very distinct handles, rotates 45 degrees between shots. (01:20:05)
Continuity mistake: Brigid O'Shaughnessy goes into the kitchen to make some coffee and hands Kasper Gutman the $10,000. He shows Spade nine bills and claims that she pocketed one of the thousand dollar bills. Spade gets Gutman to admit that he, "palmed it" but if you look closely the money is never out of our sight and he never palmed anything. (01:23:45)
Continuity mistake: Kasper Gutman goes wild cutting the Maltese Falcon continuously with his knife, but in one of the inserted close-ups of him he's just standing there not doing anything. (01:28:40)