Continuity mistake: When Luke removes Vader's mask, Anakin's eyebrows have been removed in the 2004 DVD. However, a part of his left eyebrow can still be seen in some shots, and it even changes size a few times. (01:55:50)
Continuity mistake: In the sequence of the Emperor torturing Luke, there are several close-ups of Vader. Look at his helmet - it goes back and forth between being clean and being dusty.
Continuity mistake: After the Death Star explodes, in the first shot of the Ewoks, a grey one is standing next to Chewbacca (who can be seen on the extreme right). In the next shot, this Ewok has disappeared, and another one is standing next to C-3PO. This Ewok has disappeared in the following shot, and a third one, who was nowhere to be seen in the previous shot, is now standing in front of Chewbacca. Also, C-3PO, Chewbacca and the Rebel next to him are standing in different positions between shots. (00:58:15)
Continuity mistake: When Jabba pulls Leia's chain in the sail barge, Bib Fortuna is standing on the right side of the screen, a few meters away. He then takes one step forward, but in the next shot he is suddenly standing behind Leia, as he's pushing her against Jabba. He was too far away from them in the previous shot to have reached them that quickly.
Continuity mistake: When they get ambushed in the shield generator complex, an imperial in black appears from the right of the screen in front of the ledge with the railing. Han throws the container in his hands at the imperial. If you notice, the imperial actually begins to jump over the railing before the box even hits him.
Continuity mistake: When Luke and Han are being executed on Tatooine, Han says his eyes are getting better but still bad. Then he looks directly at Luke and says "You're gonna die here." In the very next line of dialog, Han's head is turned a different way. It looks like it was a different shot.
Continuity mistake: At the end of the scene when the Emperor and Darth Vader walks through the Death Star's hangar, you can see that the Emperor walks past a squad of grey suited commanders. But in the next shot there are only white dressed storm troopers and scout troopers on the right side of the Emperor. And if you compare the last shot in the scene with the earlier shots you can see differences in the soldiers' placements. (00:37:45)
Continuity mistake: When Luke pulls Vader away from the edge of the abyss, a wall can be seen behind them, quite close to them. But several times earlier in the movie, there was no such wall in this area of the Emperor's throne room. (01:52:40)
Continuity mistake: When Vader's shuttle is approaching the Death Star, the crew in the control room of the Death Star are wearing black gloves. One of them then reaches forward to press a button, but in the close-up of his hand pressing the button, the hand is not wearing gloves at all. This can only be seen in the widescreen version. (00:02:25)
Continuity mistake: During Luke and Vader's conversation on Endor, as Vader says, "That name no longer has any meaning for me," he is pointing the hilt of Luke's lightsaber at Luke's chest. In the next shot facing Luke, the hilt is nowhere to be seen, even though it should be, because of its position in the previous shot. (01:20:35)
Continuity mistake: In the scene of the rebels planting explosives in the bunker, the first shot shows someone with gloves planting an explosive. Then it cuts to a wide shot of Han's team and none of them are wearing that style of glove. (01:51:10)
Continuity mistake: When R2-D2 is assigned to his duties in Jabba's palace, another droid (EV-9D9) says, "But you'll soon learn some respect." and her arm is in a different position from the previous shot. In the following shot, her arm is in its original position. (00:11:10)
Continuity mistake: When the Emperor is torturing Luke, in the shot after Luke groans, "Father, please", Vader and the Emperor are standing further away from each other than in the previous and following shots where both are visible. (01:51:20)