Continuity mistake: When Kuzco and Yzma make a dive for the potion bottle, Yzma is turned into a cat simply by landing on the potion bottle. This suggests that a person only needs to touch the potion in order to be affected. However, when Kronk and Yzma are serving Kuzco dinner and are trying to avoid poisoning themselves, Kronk pours his potion drink on himself and is not affected.
Continuity mistake: When Aladar is trying to help Eema get up, his eyes turn blue in one shot and in the next, they turn back to the usual green. The same thing happens at the end of the movie, when Aladar's baby hatches out of the egg.