Continuity mistake: During the battle of Hoth, Wedge flies a full circle around the AT-AT walker and when the walker begins to fall, you can see the cable around its legs, but in a side view of the walker falling, the cable is nowhere to be seen.
Continuity mistake: When Han attempts to shoot Vader, Vader deflects the bolts into the walls. As he says, "We would be honored if you would join us," you can see burn marks by the door and on the wall to the left. Two shots later, the burn mark by the door has changed shape and size, and in the last shot of the scene, the other one has disappeared. (01:25:05)
Continuity mistake: Widescreen version: When Luke and Vader are fighting in the carbon-freezing chamber, as Vader says, "Only your hatred can destroy me.", the hose hanging from the ceiling behind Luke is pointed straight down, but in the previous shot, it was bent. This has nothing to do with camera angles - watch the smoke coming from it, it changes direction as well. (01:40:40)
Continuity mistake: When Vader addresses the bounty hunters, Piett says, "Bounty hunters-We don't need their scum.", and starts walking towards a corner. In the next shot, he is already at that corner. (01:03:20)
Other mistake: After Vader cuts through a pillar with his lightsaber in the beginning of the duel, the hole in the pillar is much bigger than it should be. (01:37:35)
Continuity mistake: During the battle of Hoth, the weather keeps changing between shots. The sky alternates between being totally clear of clouds, clear with some clouds, and very grey and overcast.
Continuity mistake: When Han punches Lando, Lando's cape stays on his back, but in the following shots, it's folded over his arm., before he puts it back on again. (01:29:45)
Continuity mistake: When Lando invites Han, Leia and Chewbacca for refreshments at Cloud City, we see a box containing C-3PO's remains and the head of C-3PO is looking to the right. But when the four of them leave the room, we see a close up of C-3PO's head and it is now looking to the left.
Continuity mistake: When the Imperial stormtroopers arrive to prevent Leia, Han and Chewbacca from escaping after being captured by Darth Vader, Lobot (Lando's aide) walks down the steps and stands in front of two of the stormtroopers. When we see Lando saying "I'm sorry" in the next shot, Lobot has disappeared.
Continuity mistake: When the Falcon is being pursued by the Star Destroyers after escaping Hoth, C-3PO enters the cockpit, attempting to talk with Han, but the ship shakes and he lands on Chewie. After Han says to check the deflector shields, Chewie pushes C-3PO off him, though C-3PO leaves his hand on Chewie's shoulder. In the next shot, C-3PO is suddenly standing at the other end of the cockpit, with his hand nowhere near Chewie.
Continuity mistake: Before Han is frozen in carbonite, you can see there is nothing by Leia. When the platform Han is standing on begins to drop, we return to Leia and she now has an Imperial stormtrooper standing by her.
Continuity mistake: When Han says "Watch this!" when trying to get the Millennium Falcon to jump into hyperspace, C3PO turns his head around twice.