Continuity mistake: When Sarah shouts, "Quick, this way!" and then Sir Didymus shouts, "No, not that way!" the hanging sign with the hammer hangs crookedly by only one chain. However, two shots later when Sir Didymus shouts, "You're going the wrong way!" the sign hangs properly from two chains. Then later, when the three Samurai Goblins jump in front of Sarah and the rest, the sign's chain is broken once again. (01:20:00 - 01:25:40)
Continuity mistake: All four guys are in the junk-yard and they are all about to toss their coins to see who goes to get the food. When Teddy throws his coin in the air he is wearing no dog tag necklace but when he catches the coin he is suddenly wearing the dog tag necklace. (00:22:15)
Continuity mistake: When Fievel discovers that Warren T. Rat is actually a cat in disguise, the hat tucked into his black belt disappears between shots. (00:51:20)
Continuity mistake: Notice the candle on the table in the Italian restaurant scene during Capt. Kirk and Dr. Gillian dialog. It changes height depending who is talking. (01:03:50 - 01:08:30)
Continuity mistake: When Carolyn first enters David's room at NASA headquarters, she introduces R.A.L.F. Between shots, David wraps both arms around his knees. (00:30:35)
Continuity mistake: When Jenning destroys the Ketchup bottle he only breaks the upper part while the label remains perfect. A shot later the label in the lower part is broken in two.
Continuity mistake: At the beginning when the helicopter lands, the helicopter's shadow goes out toward the rear right of it (from the pilot's perspective), but when Sue grabs her bags and walks to Walter, the shadow is now cast to the front right. Since Sue got out and was standing next to it, the helicopter did not move in the meantime. (00:03:15)
Continuity mistake: When Jack Burton and the rest of the gang escape from the Wing Kong Trade Centre the first time, the guards fire at the left side of the bus breaking the windows and making holes in the bodywork. When we see the bus a few seconds later as it is driving away, it appears undamaged.
Continuity mistake: When Tommy Tong breaks Jarrel's stick, the broken part of the stick differs between shots. (00:33:40)