Continuity mistake: When Baby's family drive into Kellerman's you can see the back of the mum's head, and her hair is blonde. In the rest of the movie she has red hair. This is because the original actress cast as her mother changed after filming had already begun. (00:02:55)
Audio problem: In the scene where Penny and Johnny are teaching Baby their dance routine you see Penny putting on a record, if you look closely you can see that Penny moves the arm to put the record on then right away you see her taking the arm away even though the music has started. Even if it's a directorial device for us to hear different music than they do, it's still a mistake because she's not actually put the record on, meaning they've not got any music playing. (00:36:35)
Visible crew/equipment: After Johnny and Baby do their dance at the end of the movie they walk over and Baby's dad stops them. You can see their marks where they are supposed to stand. (01:34:35)
Continuity mistake: When Max is talking with Tito at the end during the final show they're both talking and standing next to the record player. In the next scene they're both standing way off stage (no longer next to the record player) and then Max enters on stage and Tito walks up behind him. (01:27:25 - 01:28:25)
Other mistake: In the scene were Patrick breaks the car window, when he walks to his seat you can see a point of red light (like a laser) on his back. (00:40:45)
Continuity mistake: In the scene were Johnny is fighting Robbie, his belt breaks, and is hanging down. Next shot it is fastened again. And then it is hanging down again. (01:11:45)
Continuity mistake: When Baby and her Dad are on the porch, having a serious conversation about the money for the dancer's abortion, the Dad's collar on his jacket is turned up, then down, then up again. (01:19:35)
Continuity mistake: In the scene where Patrick has just given his speech about how wonderful 'Baby' is, he finishes, walks to the side of the stage, puts down the mike stand and takes off his jacket. In the very next shot, he puts down the mike stand and takes off his jacket again. (01:30:10)
Revealing mistake: After Johnny leaves, they show Baby standing on the porch of her family's cabin. If you look in the background you see two people waiting for their cue before they start walking. (01:24:30)
Continuity mistake: When Johnny has realized that he locked his keys in the car, he takes the pole and breaks one of the car windows with it. The hole he made was about the size of a fist. In the next scene however, the hole in the window is twice as big as it was before. (00:40:35)
Visible crew/equipment: Right at the beginning of the film, 'Baby' is having a group dance lesson with Penny. On the wide shot with Penny wearing a red dress and showing the dance steps you can visibly see a sound boom at the top of the screen. [Fixed in Collector's Edition.] (00:05:40)
Revealing mistake: Knee pads are visible on Johnny during the dance at the end.
Factual error: In the scene when Baby is changing her clothes in the back of Johnny's car the lights and shadows in the car are moving in the wrong direction. (00:49:30)
Continuity mistake: In the scenes where Johnny and Baby have to break into the car, when Johnny looks in to find his keys, it's raining, when he turns to grab the post to break the window, the sun is up and the ground is dry, then when he turns back to actually break the window, it's raining again.
Factual error: After the part where they were at breakfast and discussing the idea of leaving early, you can overhear the radio and the announcer says, "Oh, those Mets! What a team! Finally broke their 22 game losing streak!" The longest losing streak for the New York Mets is currently only 17 games, which was in 1962, a year before the setting of the movie. (01:00:33)
Continuity mistake: When Baby is kissing Johnny after he talks about women using him, the blankets are tucked into her armpit, but then in the next shot they are neatly lying around her waist. (01:05:00)