Continuity mistake: In the final scenes at the airport, when Rick is talking to Major Strasser, the epaulettes on Strasser's shoulders alternately appear and disappear.
Continuity mistake: When Bogie is reading the note from Bergman, it is dissolved by the heavy rain and he is dripping wet, so is Sam, who delivered the note. But then he is standing on the step of the train totally dry.
Continuity mistake: When Rick goes to see Ferrari at the Blue Parrot the first time, there is a bottle on the table between them. Ferrari is shown taking the cap off the bottle, pouring a drink, and then returning the cap to the bottle. In the next cut, the bottle is gone, and in the cut after that the bottle is back, but without the cap, which should still be on it.
Factual error: Major Strasser uniform trousers have a double stripe running down the side. Double stripes were reserved for General Officers therefor Strasser would not be entitled to wear them.
Continuity mistake: In the scene when Rick is discussing exit visas with the attractive Bulgarian woman (and what she is contemplating doing in order to get them) Rick's hands change from holding a drink to holding a cigarette between shots.
Revealing mistake: Dooley Wilson could not play the piano and so a pianist was playing offstage while he sang the songs. Just look at Dooley's hands whenever he is 'playing' the piano and you can immediately see that this is true.
Factual error: When Rick is talking about the German guns shelling near Paris, he describes them as 77's (non-existent) - likely meant the famous 88's used as anti-aircraft and tanks as well as for wheeled guns. [The line was originally "88s" but was changed at the request of the War Dept. so as to not tip the German's hands that we knew about the 88s.]
Continuity mistake: When Rick and Renault are sitting at a table outside Rick's Cafe, a bottle disappears from the table between one cut and the next and then reappears. In the shot without the bottle, there seems to be a champagne bottle at an angle in the background, something that is not visible in the other shots when the first bottle is on the table.
Continuity mistake: When Ilsa is in Laslo's bedroom, she is shown from behind looking out the window at the street below, then after an edit she is shown looking at the street from out side the window. The problem is that the first shot showed her looking through a roll-type window shade, and the second is a slat-type Venetian blind.
Continuity mistake: After his bar has been closed, Rick discusses his financial situation with Carl. In long shot you see Carl wearing his glasses on his forehead, in a closer shot, the glasses are on his nose.
Continuity mistake: When Ugarte (Peter Lorre) gives Rick the "Letters of Transit", Rick places them in the right breast pocket of his jacket, but when he goes into the other room, to the rear of the piano, he removes them from his left breast pocket.
Revealing mistake: Near the very beginning of the film, we see the Moroccan police car with five officers speeding through the busy street with siren blaring and people jumping out of the way. The siren continues to be heard, as the scene shifts a total of five times within eight seconds to show the panic and confusion in the streets. As the siren continues, the scene shifts back to a glimpse of the police car once again, which is going through the same section of street, with the same buildings and painted mural and the same actors on both sides of the street. Watch the man in the white suit and hat jump out of the way of the same car two times within nine seconds.
Continuity mistake: In scenes at Rick's Cafe, Captain Renault is wearing a white dress jacket with three medals. The right-hand medal, possibly the Légion d'Honneur, is first seen on a long ribbon. Less than a minute later, it is on a short ribbon; over the next nine minutes, it becomes long, short, long. It's not a medal, it's a yoyo.
Revealing mistake: When we see the shadow of Rick opening the safe, there is also the shadow of a candle centered in the shadow of an archway. When we see Rick closing the safe, the shadow of the candle is now at the edge of the shadow of the archway; showing that the two shots were lit differently.
Factual error: The opening credits name S.Z. Sakall as S.F. Sakall, and the globe of the world which follows the credits has the USSR listed as the Union of Socialist Soviet Republics. The original name of the USSR in Russian was "Soyuz Sovetskikh Sotsialisticheskikh Respublik" which clearly translates as Union of Soviet Socialist Republics.
Factual error: The extras in the film that were supposed to be Moroccans are perfectly dressed as Egyptians.
Visible crew/equipment: The famous final scene on the airport tarmac was actually filmed on a soundstage. The airplane in the background is a scale model. If you look closely, you can notice something odd about the crew working on the plane.