Continuity: During the song "Cabaret", Sally's "cross your heart" halter dress changes from crossing left-over-right to right-over-left and back between shots.
Continuity: In "Money" Sally's nail polish is green at the beginning of the song, red in the middle, and then back to green by the end.
Anachronisms: The movie is set in 1931, but Bryan and Sally stroll down the street with defaced election posters in the background from the Presidential elections of 1932.
Continuity: When Brian thrusts the plate of cake at Sally, the cake slides off the plate and slips down to her lap. In the next shot the cake is up on her chest.
Audio/visual unsynchronized: During the song "Willkommen" when the Master of Ceremonies says "Outside, it is windy," his mouth does not match what he's saying on the word "windy".
Anachronisms: After she's tried to seduce Brian, Sally brings her record player into his room and plays a record....this is the 1930s so the record should be spinning at 78rpm. But it isn't...it's clearly playing at 33.
Revealing mistakes: The subtitles are inconsistent with how they show German speech/singing. During the opening, with Joel Grey singing in different languages, the subtitles show the German words in German. In at least one other part of the movie (when he's singing/dancing with the ape), some German words are translated into English in the subtitles. In this same ape scene, Joel is inconsistent with his pronunciation of English words that start with 'W'. Sometimes he pronounces them as if they start with a 'W', sometimes with a 'V'.