Visible crew/equipment: After the ship's captain delivers the Falcon to Sam Spade's office, he collapses on the leather sofa in the foreground. Just after Spade's secretary says, "Is he ...?", the shadow of someone's head passes over the sofa.
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)
Continuity mistake: After going through his pockets, Spade holds Joel Cairo's three passports in his hand, but if you watch closely he puts four passports onto the top of the table. (00:25:50)
Visible crew/equipment: At the end of the movie, Kasper Gutman gets ready to leave and as he passes in front of Brigid O'Shaughnessy an equipment shadow appears on her head. (01:31:15)
Other mistake: Detectives Dundy and Polhaus visit Bogart at 3:40 in the middle of the night as we see the time on his alarm clock after they walk in. In the previous shot it's impossible to tell what time it is time because there are no hands on the clock. (00:11:10)
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: As Spade speaks to Brigid O'Shaughnessy in the first scene of the movie, there's a file cabinet in between Miles' and Spade's desk. Throughout the scene, the books on top of the file cabinet move without anyone going near them. (00:05:50)
Continuity mistake: Spade pulls an orchestra ticket to the Geary Theatre out of Joel Cairo's wallet. At first three-quarters of the ticket is underneath the flap of the wallet then in the next shot the entire ticket is out of the wallet. (00:26:05)
Visible crew/equipment: Spade returns to Brigid O'Shaughnessy's apartment and tells her about his meeting with Joel Cairo. Right when he says, "He offered me $5,000 for the black bird," the shadow of the boom mike can be seen above the fireplace. (00:31:55)
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)
Audio problem: When Effie says on the phone to Archer's widow "no, not yet" her lips do not move.
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: When the two other detectives are interrogating Sam in his house, he keeps changing place.
Continuity mistake: Kasper Gutman stands in front of the Maltese Falcon and demands the $10,000 back from Spade. If you look closely the falcon is untouched without any knife marks on it. (01:30:50)
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: 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: The police visit Spade's apartment after Miles Archer murder and we see a nice tie rack with several ties hanging off of it behind the lamp near his night stand. Earlier in the movie we saw this spot when he got the call about the murder and the tie rack was not there. (00:10:40)
Continuity mistake: A sweaty knifeless Kasper Gutman places the Maltese Falcon back up on the table after they find out it's a fake, but in the next shot they show him holding the knife again. (01:29:35)
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: As Spade speaks to Brigid O'Shaughnessy in the first scene of the movie there's a file cabinet in between Miles' and Spade's desk. Throughout the scene the books on top of the file cabinet change positions without anyone going near them. (00:05:50)
