Revealing mistakes: Before Sister Mary Clarence enters the music room for the first time, the students can be heard telling the same "Yo Mama" jokes through the door that they tell once she enters.
Continuity: Some of the "La La La" scenes in the new music room show the walls as having been painted, and the piano fixed, before the scenes in which the students paint the walls and fix the piano.
Continuity: When Sister Mary Clarence meets the class, Maria walks to her seat twice between shots.
Continuity: At the competition, Mary Roberts's hands are up on her face when she hears the news that sister Mary Clarence is a fake. In the next shot they are down by her sides.
Continuity: Before the kids go out onto the stage to perform in the competition, Father Maurice speaks to them backstage. During that scene the kids' positions change several times, when they are shot to look like they are in the same position throughout the scene.
Audio/visual unsynchronized: When Mary Lazarus is teaching a student a musical scale, she accidentally whacks herself with the baton. The baton's impact and the sound effect do not match.
Continuity: Sister Mary Roberts in the street concert scene is dancing in the middle of the stage, but when the next shot appears on screen she is on the other side singing into a microphone.
Continuity: When Rita is laying on her bed listening to her Walkman, learning the music (just before her Mom arrives home and tells her she can't be in the choir or competition), Rita is looking at a page full of text. Then, just after, it's a page of music instead.
Crew or equipment visible: In the final performance of Joyful, Joyful, as the camera crane hovers over the act then changes to a shot of Whoopi Goldberg conducting and dancing with the group you can clearly see a camera move into the dancers behind Whoopi before it cuts to the next shot.
Continuity: When the nuns tell Dolores that they are teaching at St. Frances she says that was her school. However, at the beginning of the first Sister Act the text says that the young Dolores is at Saint Anne's.