Deliberate "mistake": When Cady is breaking the 'plastic' crown into bits and throwing the pieces to people in the crowd, it's not possible to have that many pieces from that one crown. She must give out at least 7 or 8 big chunks, which just doesn't truly reflect the size of the crown.

Audio problem: At the beginning of the movie when Cady is leaving her parents to go to school she almost gets hit by a bus you can hear her mom scream. In the next shot of her mom you see her scream but nothing comes out. Submitted by Stephen Edmonds

Continuity: In the scene where Santa comes in with the candy cane gram, as the camera cuts on and off of Cady, you will notice that her hands move from on top of her desk to in her lap a couple of times. Submitted by Stephen Edmonds

Continuity: When the Plastics are explaining to Cady the "rules" at lunch, an extra in a red shirt walks directly in front of the camera, and then a couple of seconds later, she walks in front of the camera again walking the same direction that she was walking the first time she passed the camera.

Continuity: When Cady enters the dance after the Mathletes competition, her sleeve is down past her arms and we cannot see her hand. In the next shot, the sleeve is rolled up and her hand is visible.

Continuity: In the wings after the Jingle Bell Rock dance, Aaron has his arms around Cady and Regina. Just as Kevin leaves we can see Aaron's hand is on Cady's shoulder, but in the next shot it is down by his side.

Continuity: At the start of the film as Cady's Dad gives Cady her lunch bag, he has nothing round his neck. But in the next shot the camera is around his neck. Submitted by Hamster

Continuity: When Cady is trying to get out of going to Madison, watch the level of her Dad's glass of water. From the first shot of the table to when he picks it up whilst saying "I think Cady's old enough..." the water level lowers. Submitted by Hamster

Continuity: In the opening shot of Cady in calculus class, as her voice-over says "I was so happy to get to math class", the big textbook sitting on her desk alternates from closed to open. This happens again after Cady says "So Cute..." Submitted by Hamster

Continuity: When Cady is outside on the field with Janice and Damian supposedly going to the back building, there is a very large shadow in front of the rugby goalpost in the background (behind Cady) which keeps disappearing / reappearing. Submitted by Hamster

Continuity: In the Spring Fling scene, when Cady and Aaron are dancing, it alternates shots between Cady's face and Aaron's. Her arm is on his shoulder in one shot and the next shot it is on his arm. This happens a couple of times in the same section of that scene. Really obvious.

Continuity: After Cady bumps into the teacher, she puts a box of Donuts onto the desk. There isn't anything on the box, then in one shot two text books appear on top of the Donut box. They then disappear in the next shot. Submitted by Hamster

Continuity: When Cady comes home from her first day her father sets down his book on the notepad on the desk as he sees her. In the next shot as she goes inside the book has moved back.

Revealing: In the scene where Mrs George is taking pictures of the girls for the Halloween concert you can see that the camera is turned off. Submitted by Ian Mugford

Factual error: While the plastics are at the mall there is a Bell Mobility booth seen behind them. This booth wouldn't be found in an American mall as they only service Canada. Submitted by Ian Mugford

Factual error: When the girls are going wild, the two Chinese girls, who made out with Coach Carr, fight and argue. There is a subtitled translation at the bottom of the screen and one of the girls' lines is translated, "Your the slut." This should have said, "You're the slut," because "your" shows possession, whereas "you're" means "you are", which is correct.

Continuity: When Regina is talking to Cady about Janis, Cady is wearing a light blue ribbon in her hair. As the scenes cut in and out of Cady the ribbon changes from front to back a few times. Submitted by Stephen Edmonds

Audio problem: When the Spring Fling Queen nominations are being announced applause can be heard for both Janis and Cady but no one in the class is clapping.

Revealing: When Cady's math teacher spills coffee all over her shirt, you can see the hand that is to your left is pulling her shirt up with her sweater and rapidly lets go.

Continuity: When we see the first shot of Regina throw a pile of Burn Book sheets to the floor, they fall and all spread out. Then she sticks a sheet about Trang Pak up and then in the next shot as she continues to walk, the sheets she first dropped behind her on the floor are all much closer together in a different position. Submitted by Hamster