Continuity mistake: The train that transports The Haynes Sisters and Wallace and Davis from Florida to Vermont is shown as being of the Atchison, Topeka and Santa Fe Railway in one sequence, and of the Southern Pacific Railroad in another. Neither railway ran on the east coast of the U.S.Jimmy Short
Factual error: After Gene Kelly sings "The Heather on the Hill", he sees more heather on the other side of the bridge. He starts across but Cyd Charisse freezes in horror, since to cross the bridge would break the spell over the village of Brigadoon. She then drops some of her heather in the middle of the path and runs back to the village. The camera cuts to Gene Kelly chasing after her, but the heather dropped on the path has disappeared.
Continuity mistake: When Piggy is seated at the dinner table, there is a bowl of fruit with a yellow lid next to it, and Piggy has in front of him a plate with a spoon on one side and a knife and fork on the other. After Piggy's mother stops him from taking some fruit, we cut back to Piggy, and the bowl of fruit and yellow lid have disappeared, and he only now has a spoon by the plate.