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.
Revealing mistake: When the Millenium Falcon fakes hitting the Star Destroyer, half of the sky is gray and the other half is black.
Other mistake: When the Falcon speeds away from Hoth just as Darth Vader steps out, watch carefully as the Falcon exits the hangar. You will notice that a very small spot of the Falcon is visible through the roof of the hangar as the Falcon exits and flies upwards.
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.
Revealing mistake: Two mistakes here: Before Darth Vader cuts Luke's hand, he cuts in half three columns. In the close-up, one can see that what held them together was a piece of wrinkled duct tape. In further shots, the tape disappears and only the scorched part of the column is visible.
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.
Other mistake: When the AT-AT (Imperial Walker) blasts the shield generator, when it explodes, you can see the glowing remains of it (only visible on widescreen DVD). It was fixed in the 2019 version.
Revealing mistake: When Han tricks the three Star Destroyers into running into each other, it cuts to the bridge crew of one destroyer being knocked around by the impact. You can see one of the officers in the 'trench' section (the lower level of the bridge) bump into one of the consoles and knock it askew, revealing it's actually a lightweight prop. For added humor, the officer that was sitting at said console then subtly tries to push it back into position before the scene cuts.
Revealing mistake: Han and Leia are arguing in the ice tunnels near the beginning. Han tells her she wants him to stay, and they stop and talk about it. Two people pass. Han moves back for the first person to come between them. The second alien-looking guy walks behind Han. His rubber mask gets caught on Han's right shoulder and bounces back into shape immediately.
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.
