Revealing mistake: When they first meet the Cowardly Lion, he jumps off of a boulder and obviously lands on a trampoline and jumps off.
Suggested correction: There is no trampoline visible. Sure, there is most definitely something he jumps off that is hidden behind the plants, but since we don't actually see it on screen, I don't see how it's a mistake.
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.
Continuity mistake: When Dorothy is holding Toto in the last scene, the dog is facing to the left, but in the very next shot he's suddenly facing to the right.
Continuity mistake: When Glinda starts to sing, a Munchkin is seen coming out of an open sewer with its lid on the side. When the angle changes, the munchkin is nowhere to be seen and the sewer is closed.
Continuity mistake: When the cyclone arrives, the farmhands let out the horses, which run wild through the farm. In the immediate wide angle there's no sign of humans or animals anywhere.
Continuity mistake: When Dorothy extinguishes the fire on the Scarecrow's arm, the Witch keeps swapping between: close, far, next to a window, plain wall; all in a matter of seconds.
Deliberate mistake: Before Dorothy is sent to Kansas there's a close-up of her shoes. All of the group's feet, Glinda's dress, and the rest of the elements around are gone and replaced by a black background. Despite being a deliberate directorial decision to give the shoes a more dramatic focus, it is really awkward to see everything disappear, nevertheless.
Continuity mistake: Just before the group starts skipping towards the Emerald city, there is snow everywhere, but in the next shot, it's completely disappeared.
Continuity mistake: When Dorothy grabs the oil can next to the tin man, the leaves he holds in his left hand change positions between shots. A leaf on the log also appears/ disappears randomly between shots.
Visible crew/equipment: When the Wicked Witch shows Dorothy the hourglass, many stage lights are reflected all over it.
Factual error: Tin doesn't rust.
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.
