Plot hole: In this episode all the students say Hollywood Arts has never had a prom before. But in the first episode, 'Pilot', Rex says to Cat after she runs out to tell Tori, Robbie, Andre and him that Sikowitz wants them to come back into the classroom, "Just like you wanted a date to the prom last year."
Continuity mistake: When Cat, Beck, Robbie, Jade and Andre are telling Tori about why they faked the Ping Pong team, it shows a flash back of two years ago when Tori hadn't started at Hollywood Arts yet. But in the background of the hall when they are asking for Sikowitz to help them, Tori's locker is there - how can her locker be there when she hasn't even started at the school yet?
Continuity mistake: In "Survival of the Hottest" or "Stuck In a RV", the scene after Cat runs to go to the bathroom you will see that Jade & Beck enter the RV and Jade has her sunglasses on top of her head. The scene then goes to Trina & Tori, back to Beck & Jade, Trina & Tori again, the back to Jade & Beck, but Jade's sunglasses vanish. Then it goes back to Trina & Tori, then Beck & Jade and the sunglasses are on her head again.
Plot hole: Some episodes act as though Drake and Josh was real and some act as if it is a T.V. show. In the episode with the new principal, Helen from Drake and Josh is the same character as she was in Drake and Josh and becomes Hollywood Arts' new principal. But, in the episode when Trina's play-scene was sabotaged, Cat and Tori refer to Drake and Josh as a television show.
Other mistake: In season 3, episode 10, "Tori Goes Platinum", Robbie gives Tori a chocolate leaf-blower as a present to cheer her up. Then when Robbie leaves to go join Cat at the Platinum Music Awards, he supposedly takes his chocolate leaf-blower present with him. But, in the shot where he leaves Tori's house, the bag that the chocolate leaf-blower was in is still on the floor.
Deliberate mistake: Season 1, episode 9: When Jade finds out Sinjin is in her house, he runs, then Tori says, "OK, no more interruptions" or something like that. Right when she says that, if you look on her screen, Sinjin's video chat box is gone. How could it be gone if Sinjin did not sign out and Tori didn't kick him from chat?