Incorrectly regarded as goofs: When the second nerd is removed from the seniors' trunk, it appears the senior is lifting out a dummy, but in fact, the actor just stiffened his body. You can see him blinking.
Crew or equipment visible: When Jake Ryan and his friend are doing fake pull-ups in the gym, and they pull back, you can see the dolly track. (Full-screen version only)
Continuity: When Sam is lying on the couch, talking to her father, her blanket changes positions.
Continuity: When Caroline and Jake are slow dancing at the school dance, Caroline's hair changes between shots.
Audio/visual unsynchronized: When Farmer Ted is driving Caroline around she says, "Looks like rain! Time to put the top up!" her mouth is just laughing, not speaking.
Revealing mistakes: When Caroline shows Farmer Ted the locks of hair that got cut off, they are much longer and darker than the section missing from the back of her head.
Revealing mistakes: When Caroline steps out of the Rolls-Royce, you can tell that she stepped onto a box or platform before walking off.
Revealing mistakes: In the school auto shop when Farmer Ted tries to get into the car with Sam, he can't open the door because it is locked and Sam had to reach over to unlock the door for him. There is no door post for the lock to engage, so even if the door was locked, it would still swing freely.
Continuity: When Jake Ryan goes to Sam's house looking for her, and Long Duck Dong answers the door, the hot water bottle Long is holding moves from the top of his head to the side of his neck, and back.
Continuity: When Mr. Baker is driving Mike and the grandparents to the wedding, Grandma Baker lets Grandma Helen in the car first. Because there was little room in the front seat, Grandma Baker squats down along side of the far side of the car pretending like she is sitting in the front seat Mr. Baker pulls away without Grandma Baker in the car.
Revealing mistakes: When the family is going to the wedding, the grandparents all pile into the car. However, when the car is backing out of the driveway, you can see one of the grandmothers is outside of the car squatting so that she isn't seen.
Errors made by characters (possibly deliberate errors by the filmmakers): When Samantha is in independent study, the questionnaire that she is filling out says "CONFIDENTAIL" on the top.
Boom mic visible: When Sam is talking to her mom in the kitchen, you can see the shadow of the boom mic on the cabinet between them.
Continuity: Sam puts a can of Diet Coke on her lunch food tray in the school cafeteria, but when she enters the lunch room with her friend, she clearly has a regular can of Coke on her food tray.
Continuity: Jake won't let Ted drive his car, a Porsche, because Ted doesn't know how to drive a stick (manual transmission). Near the movie's end, Jake sees Ted and Caroline in the church parking lot and stops his Porsche to look. When he continues forward and turns into a parking space he can be seen bringing the shifter backwards. This would indicate an automatic transmission. A manual transmission would require him to shift forward, into first gear.
Revealing mistakes: In the opening sequence, a geek is having trouble opening the pad lock on his locker. When the locker is finally opened, some of the objects that fall out are obviously falling from overhead and not from the locker.
Continuity: When Long Duck Dong answers the door the top left glass is clear and the right is frosted, then the left becomes frosted after opening the door. From the outside.
Continuity: When Jake puts Carolyn in the Rolls Royce, he clearly puts her legs inside the car. Yet before he lets Ted leave he puts her legs in before he shuts the door.
Revealing mistakes: When Ted and Carolyn are driving down the road, just after she makes the top go up and down, there is no rear view mirror. There is a bracket for one, but no mirror.
Continuity: When the grandparents are in Samantha's room sleeping and the phone wakes them up, the phone is in one position, Grandma hangs it up, and the receiver is different than before. Then when they answer it again it is in a different position. Then they have the phone on the bed.