Continuity mistake: In the Wicked Witch's room, she puts Toto in Dorothy's basket which now has a lid on both sides of it. Later when the boys come to rescue her, Dorothy walks over toward the hourglass, and picks up the same basket and it now has no lids on it (like earlier in the movie). (01:17:20 - 01:23:50)????
Continuity mistake: When the Munchkins come out onto the Yellow Brick Road, one of them comes out of a sewer hatch on the yellow bricks. It's located on the ground in front of the first small white cottage with the thatched roof, right behind Dorothy's house. Throughout this scene, the dark hatch is visible whenever we see that specific location, such as when the Wicked Witch of the West asks, "Who killed my sister? Who killed the Witch of the East? Was it you?" but as Dorothy begins to "follow the yellow brick road", there is an overhead shot followed by a front shot and the dark hatch has disappeared.
Revealing mistake: When they first meet the Cowardly Lion, he jumps off of a boulder and obviously lands on a trampoline and jumps off.
Continuity mistake: When Toto pulls the curtain back to show who the real "Oz" truly is it looks like Toto's collar got snagged or he actually had to bite it but in the next shot he pulls the curtain back so fast that it would've sent Toto flying but then he is connected back to it again.Chris Rutter
Continuity mistake: The Wicked Witch of the West's bilious green face colouring changes shades during the film. DVD showing.
Revealing mistake: In the scene where the tornado is about to hit and Aunt Em and Uncle Henry are going into the cellar, you can see that some of the trees are blowing around violently, and others aren't moving at all. (00:16:05)