Continuity mistake: During the Big Bad Cat song, Siri calls Eliza by name. Siri was never told Eliza's name.
Continuity mistake: When Donnie steals Chuckie's clothes and glasses, Chuckie puts on Donnie's shorts and complains about his eyesight. But later in the movie, when he doesn't have his glasses, it seems he can see just fine. Then, when he gets his glasses back, he says something like "I can see again."
Factual error: This mistake happens in the scene where Nigel and the babies are trapped in the bathysphere underwater, and Nigel is on the radio, chatting with Marianne. Nigel reports: "Well, one little girl is rather pouty, and someone needs a diaper change." However, it has been pointed out in episodes of 'The Wild Thornberries' that Nigel is from England. Even though Rugrats Go Wild was produced in the United States, Nigel should've used the word 'nappy' instead of 'diaper'.
Continuity mistake: When Donnie takes Chuckie's clothes and then throws Chuckie his own shorts, Chuckie puts them on and the shorts fall right off. Chuckie makes a comment about his shorts being a lot bigger, yet Chuckie's shorts seem to fit Donnie perfectly and a few minutes later Donnie's shorts now fit Chuckie just fine.