Continuity mistake: In the episode when it's Kenan's birthday, Kenan and Kel are looking for Kenan's present in Kenan's parents room. As they're searching, Kel throws some of Kenan's parent's clothes all over the place. But then when Kel throws the snowglobe, there is practically no mess, but just a few clothes on the floor - less than before. Some clothes on the bed disappear as well.
Continuity mistake: In the episode where Kel is banned from ever going in the Rockmore house again, Kel sneaks through Kenan's window, scaring Kenan. Kenan jumps back in fright and knocks the lamp from his bedside table and it rolls onto his bed. However in the very next shot the lamp is suddenly back and upright on the bedside table. In the next shot the lamp is now back on the bed.
Continuity mistake: Kel comes into Rigby's and sits on the counter and takes of one of his trainers, after he has been handing out fliers. He puts it on the counter so the sole of it faces the camera all the time, yet during shots it suddenly changes so that the top of the trainer faces the camera.
Continuity mistake: In the episode when there is a rat in the store, there is a scene where Kenan and Kel are discussing the rat. There is a lady in the background holding a green shopping basket. Then in a following shot the same lady is now suddenly holding a red basket. Cut to the shot where she runs out of the store screaming, and suddenly her basket is green again.