Continuity mistake: When Molly takes Mikey into work and he is under the desk, Rona is still wearing her shoe. Yet when the scene changes, her shoe is missing when Mikey starts tickling her foot. Then when the boss realises that Mikey is under the desk, her shoe is back on. When the shot changes again, her shoe is off.
Continuity mistake: When Mikey has a bad dream, John Travolta goes into his room to comfort him. He picks up a Popeye doll and there is nothing next to him. In the next shot, a Pee-Wee Herman doll appears.
Continuity mistake: When John takes the kids to the movies and is trying to weasel some free popcorn, it is obvious that someone shakes the baby girl to make her cry.
Continuity mistake: When James and Molly go outside the apartment to argue away from the kids, the front door, which is behind James, keeps closing slightly then opening slightly many times throughout the scene.
Continuity mistake: Towards the end of the movie, Molly tells James not to go back to the airport because its pouring rain. If you look in the background, you can see that it is obviously daylight and the sun is shining, but in the next shot it shows that outside it is raining.
Continuity mistake: When Mikey goes to the toilet he pulls down his white trousers. When he's done and James lifts him from the toilet his trousers are back on. No one had time to pull them up though.
Continuity mistake: When Mikey is underneath the desk and goes to put white out on the man's shoe there is already white out on the shoe. Probably from a previous take.