Continuity mistake: In the "Dance at the Gym" scene, while everyone is doing a pelvic swivel with their partners, Riffs arm is around Graziella's waist. In the next shot, his arm is down. (00:32:30)
Continuity mistake: In the prologue of the movie, two guys on the Sharks throw yellow paint on Baby John, Arab, Action, and Snowboy. When they are talking to Lt. Shrank and Officer Krupke, they are all clean, but wearing the same clothes as earlier. (00:13:05)
Continuity mistake: When Glad Hand is telling them about the get-together dance at the gym, you can see A-Rab putting his arm on Action's shoulder, then in the next shot he does it again.
Other mistake: During "Cool," Baby John spins around and when he stops with his arms spread out, his right foot stumbles a little. (01:58:15)
Audio problem: When the sharks are singing "We're going to hand them a surprise tonight" in the quintet version of Tonight, someone sings the wrong note on the word "Tonight". (01:33:20)