Continuity mistake: Leia and Han become annoyed with C3PO's chattering, and Leia turns him off. However, if you watch him in the background, you can see his body move as he breathes.
Continuity mistake: During the lightsaber duel, Vader hooks Luke's lightsaber out of his hand. When Luke summons it back to his hand, it is not lying in the same place as it landed. This can be seen from the lines on the floor.
Continuity mistake: When the officers on Hoth are discussing that the shield must be shut, Leia is standing in front of a spaceship. Immediately, she is several feet back leaning against the spaceship.
Continuity mistake: When Luke is hanging upside down in the monster's cave he uses the Force to get his lightsaber. In the shot from Luke's POV it's about 3/4 buried in snow, but in the reverse it's only about 1/4 buried.
Continuity mistake: In the shot from behind Luke right before he falls into the carbon-freezing chamber, Vader's lightsaber is pointed at his chest, but in the previous shot, the sabre was held in a different angle.
Continuity mistake: In the second shot of Luke in his X-wing after he leaves Hoth, some white wires on his right are in a different position from the previous shot. This also happens in the third shot of him as he's approaching Dagobah.
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: 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.
Suggested correction: The cable is thin and we only see closer in shots until the walker falls, but you still can see it, barely in 1080p, right as the head hits as a line between the top of the front leg connecting to the back leg.
Continuity mistake: When Luke crashes on the snow he tries to open the cockpit pushing the canopy. A shot later he is pushing the windshield. This changes back and forth several times.
Continuity mistake: After Luke's snowspeeder crashes on the snow, right before he exits, there's no damage on the right window. From the outside shot it's broken all over.
Continuity mistake: In the original 1980 release of The Empire Strikes Back, the group accompanied by Billy Dee Williams just walked from the deck with the Falcon inside the halls of the city. There is a man fixing a wall and next to that man is a window, the window shows a blue sky with a couple of buildings that were obviously drawn in the scenery. However in the last scene where Harrison Ford was hugging Billy Dee Williams the sky was orange. This shot only last for a second as the round small window is drawn wrong. But all of cloud city is a painting so its no surprise.