Continuity mistake: When they first meet the Tin Man, the Scarecrow is holding an apple in each hand. He drops the one in his right hand but the other one disappears when he reaches for the oil can. Later when they all walk away both apples, and the one that Dorothy dropped before, are gone. (00:44:05)????
Continuity mistake: The Munchkin Mayor's watch keeps changing time, from nearly to the hour, to twenty after the hour.
Continuity mistake: When the companions are walking down the corridor to the wizard's room, Toto is on their left side. Then, the camera view suddenly cuts to being behind them, and in which case, Toto is suddenly on their right side.