Other mistake: In the original version, in the first wideshot of the Super Star Destroyer, on the right side of the screen, the light of a Star Destroyer (but nothing else of it) can be seen just flying through space for two seconds before it disappears. This mistake is fixed in the Special Edition.
Continuity mistake: After Leia, Han and Chewbacca walk down the stairs in the carbon-freezing chamber, as the shot ends, Han is turning towards a stormtrooper behind him. In the next shot, he is turned in a different direction, and Leia's head is facing another way. The position and existence of some of the people around them changes between the two shots as well. (01:31:10)
Other mistake: When the Star Destroyers are seen for the first time, in the second shot, some of the TIE fighters that fly over a Star Destroyer are transparent.
Audio problem: After Han goes to the command centre during the battle on Hoth, Leia says to a controller, "Send all troops in sector twelve to the south slope to protect the fighters," but the words don't match her lips. (00:30:35)
Continuity mistake: After the carbonite block is pulled out of the carbonite freezer, there's a close-up of Leia leaning towards Chewbacca. In the next shot, she is not leaning on him, and then Chewie pulls her towards him again. (01:33:05)
Continuity mistake: When Vader cuts through three poles at the end of the lightsaber duel, there are different poles in the shot where he cuts through them and the next shot where they fall. (01:45:50)
Continuity mistake: When a one-legged 3PO is standing in the Millennium Falcon, begging R2-D2 to fix him, he is holding the severed leg by the knee, with the foot closest to the floor. Some shots later, he is holding it by the foot, with the knee closest to the ground.
Continuity mistake: When Lando releases Leia and Chewbacca, as Leia says, "What do you think you're doing?" her body is turned in a different direction from the previous shot, and she's holding the blasters differently. (01:37:55)
Continuity mistake: When Janson (Wedge's gunner) fires the harpoon at a leg of an AT-AT, in the first shot of the snowspeeder flying around the AT-AT, the speeder casts a shadow on the snow. In all other shots of this sequence, there is no shadow of the snowspeeder.
Continuity mistake: When Han and Leia kiss in the Millennium Falcon, Leia's arms are around Han's head in the wideshot, but not in the close-up. (00:49:55)
Continuity mistake: During the escape from Hoth, C-3PO is far behind Han and Leia as they are running to the Millennium Falcon after the cave-in blocks their path. When they reach the door, he is much closer to them. (00:32:40)
Continuity mistake: During the escape from Cloud City, Chewbacca is shooting at the stoormtroopers while R2-D2 tries to open the door. The wall he is hiding behind keeps changing between shots, and the burn mark on the wall also changes a few times, without any laser beams hitting it.