Continuity mistake: When Luke is attacked by the ice creature all the scars are on the right side of his face, but right before he talks to Obi-Wan you see a big scar on the left side of his face, then when he talks to Obi-Wan you can see there are no scars on the left side of his face.
Continuity mistake: When the stormtroopers push Leia into the cell in Cloud City, she is wearing a completely different outfit from when she was taken captive. (01:25:20 - 01:28:35)
Continuity mistake: When Han and Leia are bickering in the corridor on Hoth, Han says, " Well, the bounty hunter we ran into on Ord Mantell changed my mind." In the next shot, behind them, there's a man walking past them that wasn't there in the previous shot. (00:05:55)
Continuity mistake: When Yoda is teaching Luke, he is strapped to Luke's back in a rucksack. When Luke puts Yoda down, the little Jedi master is still inside the bag. Luke then reaches for his jacket, and in the next shot of Yoda, he has in a few seconds managed to get out the bag and is now sitting next to it. He is not even sitting in the same place as in the previous shot, and is also holding a walking stick he didn't have when Luke put him down.
Continuity mistake: As noted in another mistake, when Han, Leia and Chewbacca are taken captive in Cloud City, two of the stormtroopers change position between shots. This also happens to some of the other troopers, as well as to Lobot, Lando's aide. This is best seen in the widescreen version.
Revealing mistake: After C-3PO gets shot, as Chewbacca walks over to the door, his right foot crushes one of the steps on a small set of stairs. (01:19:25)
Continuity mistake: When the Rebels pick up the signal of the Imperial probe droid, general Rieekan says, "Princess - we have a visitor." In this close-up, his head is straight, but in the next shot, he is standing in a different place, leaning forward. (00:17:35)
Continuity mistake: At the fight between Luke and Darth Vader, after Luke pushes Vader to fall down from the top of the hibernating cabin, he looks down with the lighting light sabre in the hand. He goes back and we hear the switch-off sound of the light sabre, he comes back three meters left of the point he looked down and in his hand is the switched-off sabre. But as he goes back before this, we can see the end of the prop-light sabre taken out of Luke's hand and obviously the off-prop sabre is given in his hand.
Continuity mistake: As Major Derlin and another Rebel officer talk before the shield doors are closed, another officer walks under the starship Leia's standing by. In the next shot, he's gone. (00:11:30)