Continuity mistake: When Carrie hides in the guys locker room she videos John saying "Let's just say, at tonight's away game I'm gonna be scoring more than baskets". In a later scene when Carrie replays the video to Kate he says "I will have you know, at tonight's away game I'm gonna be scoring more than baskets".
Continuity mistake: The school's bear mascot in the beginning (when Ashanti's character is being introduced, and she's cheering) is first shown with pom-poms, yelling, "Heather's hot." The next shot 1 seconds later, the mascot is breakdancing and has nothing in his paws/hands.
Continuity mistake: In the gym after Heather puts estrogen into John's "Bulk Up" tub, pay attention to when John takes out the first scoop. It disappears in the next shot, then reappears in his hand later. (00:24:10)
Continuity mistake: When they're in detention, just before Heather starts talking there's a chair next to her with a black bag on it. The next time we see it the bag has moved slightly. (00:14:05)
Continuity mistake: When Scott is talking to Kate in the school lobby about how he's supposed to be a spy for John, pay attention to the background when they're both staring into each others' eyes. In one shot there are two people by the pillar, 2 seconds later they're gone. Then Kate says "Go, fight, roar" and suddenly those two people are there again. (00:41:25)
Continuity mistake: When Heather is asking John Tucker about whether or not he's cheating on her PE classmates, pay attention to the two handbag straps (one black/one white) on her right shoulder. In some shots the white strap is covering the black one, and in others they're both side by side. (00:13:15)
Continuity mistake: In the classroom scene where Scott and Kate are talking (just before all those guys turn up with flowers for Kate), the colour of her pen changes from green to red between shots. (00:37:15)
Continuity mistake: When Kate and John are talking on the boat, the amount of visible skin on Kate's left shoulder changes between shots. (00:58:20)
Continuity mistake: At the party near the end when John is trying to tell the audience about how it's wrong to lie, pay attention to Beth's handbag. After Kate throws the cake at John, her handbag suddenly disappears. When the food fight gets going, both Carrie's and Heather's bags disappear also. (01:22:40)
Continuity mistake: Near the beginning where the guy calls round Kate's house with brownies, we see Lori with two boxes stacked up behind her. Notice the upper box - in the first shot it's blank, but the next time we see it it reads 'kitchen'. The box is also open in a different way.
Continuity mistake: When John is trying to convince Kate outside the school that him saying "an '82 Bordeaux that you wanna uncork and pork" was just locker room talk, pay attention to the background. A woman wearing a black jacket and carrying a red and white bag walks past twice. (01:12:35)
Continuity mistake: When the girl is hiding in the locker recording what John Tucker says, she says a few things whilst the camera is recording, but later on when the tape is played at Johns party, we can hear what he said, but the girl who was talking whilst recording, her comments are not present.
Continuity mistake: When the girls are in the bathroom and Beth says "Not that slowly. We don't want him to think you're retarded.", notice how she's standing right in front of the cubicle door. In the next shot she's standing in the middle of the room. (00:36:15)
Continuity mistake: In the cinema where the genital herpes incident occurs, when the girl that John is with stands up to leave - notice the guy with the afro wearing a yellow t-shirt in the row just behind them. In the very next shot he's suddenly gone. (00:20:50)
Continuity mistake: Near the end of the film when Kate is apologising to John, the amount of hair hanging over her right ear changes between shots.
Continuity mistake: When Carrie, Beth and Heather demand to know what Kate and John got up to on the boat, pay attention to Heather's scarf. Its status changes between shots, including a brief moment where it appears on her other shoulder. (01:00:10)
Continuity mistake: During the first scene where we see John Tucker, he is playing basketball. Between shots his headband changes from black to red to black again.
Continuity mistake: At the beach, when Kate's getting there, you can see her bra strap; the next shot, when she turns around, her shirt's covering it.
Continuity mistake: In the scene where John finishes talking to Kate on the phone and reverses his jeep into the trash cans, notice how the girls are lined up when they're seen laughing. The next time we see them they're lined up in a different way. (00:55:45)
Continuity mistake: In the gym where the teacher talks about combining all gym classes and how 'we all hate each other', we see a shot of the bench and a bunch of girls sitting down. If you look to the left you can see Beth sit down. In the very next shot Beth can be seen walking behind the teacher. In fact this scene has several continuity errors with regards to people walking around, especially before and after the goth girl says 'my name is Lucretia'. (00:08:55)
