Continuity mistake: As Porky's Riverboat nears the draw bridge, you see Pee Wee activate the bridge so that it begins to lower. Look at the angle of the bridge as Pee Wee is running by it, making his getaway. The bridge is almost down. The scene cuts to the River Boat's view and you can see that the draw bridge is all the way up and just starting to come down.
Factual error: Blossom is driving a 1958 corvette in 1955.
Continuity mistake: When Balbricker and Snooky reunite on the beach, she drops her hat and his falls off when they run to each other. In the next shot when they are lying down on the beach they both have their hats back on.
Factual error: A lava lamp can be seen on top of Miss Webster's bar in her apartment. This movie takes place in 1955. The lava lamp wasn't invented until 1965.
Factual error: During the graduation scene, an American flag can be seen that has fifty stars on it. Since this movie takes place in 1955, the flag should only have forty-eight stars.
Continuity mistake: The principal, Mr. Carter, had the first name Floyd in the first two films but at the end of this one Beulah calls him Harold.