Continuity mistake: When the Drapes are singing to Allison/Baldwin/Mrs. Vernon Williams, the song, "Gee, I Love that Girl" in the speeding cars, Hatchet-Face's gold earrings are on, then off, then on again. They are seen again in other scenes.
Continuity mistake: In the very beginning of the film when all the kids are leaving school and Lenora is standing on the steps watching Allison talk to the drapes at first her hair barrette in on one side of her head and the camera goes to Cry-Baby and Allison. When the camera switches back to Lenora her hair barrette has somehow moved to the other side of her head.
Continuity mistake: When Cry-Baby (Johnny Depp) sings, "Doing time for being young," he rips his shirt wide open, but in the next shot the shirt's only half open, then in the following shots it's completely open again.
Continuity mistake: Early in the movie, when the Drapes are chasing and then pass Mrs. Vernon Williams' car, they repeatedly drive past the same trees on the roadside, about six times.