Continuity mistake: You see a Flying Monkey with Toto before he gets picked up. (01:15:30)
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)
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: In Munchkinland, when Dorothy walks the road and everyone sings "Follow the yellow brick, follow the yellow brick road," the angle cuts and a group of Munchkins have suddenly appeared in the center of the previously empty road. Dorothy was standing on the farthest point, so they had half a second to walk 10 meters, which is impossible.
Continuity mistake: The Lollipop Guild teleports all over the scene. As Glinda departs, they are behind Dorothy. As Glinda's bubble rises, several Munchkins run to where she was and wave goodbye, green shirted Lollipop Guilder (Jerry Maren) among them. Cut to Dorothy and Jerry's still behind her. (00:32:40)
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.
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)