Visible crew/equipment: When the Wicked Witch shows Dorothy the hourglass, many stage lights are reflected all over it.
Revealing mistake: After Scarecrow bounces off all the fence rails and goes back to do it again, the film is simply being rewound - the fence rails vibrate before the Scarecrow actually hits them. (Deleted scene - which are valid mistakes.)
Continuity mistake: When the Wicked Witch tells Nikko "throw that basket in the river and drown him" The basket with Toto in it moves from one shot to the other in its position to the hourglass. (00:16:45)
Other mistake: As the Wizard is pulling his curtain closed, he says the famous, "Pay no attention to that man behind the curtain," in a loud, booming voice. But he's turned 180 degrees away from his microphone, which we see a second later needs to be right in front of his mouth to make the booming voice effect. (01:28:40)
Continuity mistake: When Dorothy and the Scarecrow first enter the apple orchard, in long shots, the ground around the trees is brown, barren and furrowed. However, in head shots of Dorothy, the ground appears lush and grass-covered. (00:39:35)
Factual error: Tin doesn't rust.
Suggested correction: While tin itself doesn't rust in the same way iron does, it can corrode and oxidize, especially when exposed to acidic conditions or moisture.
Continuity mistake: In Munchkinland, when the Wicked Witch of the West tries to grab the ruby slippers, the curtain hanging out of the window changes positions between shots.
Continuity mistake: At the Emerald City entrance, the close-up of the shoes shows a straight, thick, brown road on the sides, absolutely nothing to do with the pattern seen in the wide angles.
Continuity mistake: After the Witch leaves, Glinda tells Dorothy, "You may get up, she's gone," and turns to the right. In the next shot, she hasn't turned around yet.
Continuity mistake: The Scarecrow extends his arm holding the heart but in the next shot his arm is down again.
Continuity mistake: After the Witch has melted, the Tin Man turns his head and looks at the Lion. In the next frame he is facing straight.
Continuity mistake: In the farm, after Hunk the farmhand has had his finger smashed, he scolds Dorothy. When she starts to leave, he hammers his hand and takes off his glove, shouting and turning around in pain. The angle swaps to a wide angle and he is working totally calmly with both gloves on.
Continuity mistake: Dorothy arrives home and there's a man fixing a cart whose finger gets smashed. In the wide angle his right hand is on the wheel, but a frame later in the close-up it's not.
Continuity mistake: When the movie begins Dorothy is running and Toto is a meter to the right of her. When she kneels down, he is behind her.
Continuity mistake: When the Witch flies off to Emerald City the monkey is standing by the window sill. The outside angle, where the window and rest of the set are a matte painting, has the Witch superimposed, but not the monkey. (00:57:56)
Continuity mistake: The Munchkin with the certificate of death sings that Dorothy is intelligent. He and another munchkin are standing face to face in front of her. Half a second later they are meters away from each other, standing to the side of Dorothy.
Continuity mistake: As he holds the Wizard's balloon, the Tin Man has his heart shaped clock attached to his chest at the sixth rivet. The next time we see him several seconds later it's attached to the third rivet. (01:34:50)
Continuity mistake: The house we see in the cyclone has all of it's windows intact. When it lands they're all out. (00:18:40)
Other mistake: A shiny snap on the Lion's left foot can be seen gleaming in the stage lights as he says, "I hope my strength holds out" on the side of the mountain. (01:20:05)
Other mistake: In the shot after the Wicked Witch throws fire down at them they all look up at her in the wrong direction. (00:46:25)
