Krista

Continuity mistake: When the waitress is cleaning off the table after the kids leave, the plates on her tray all appear to be empty. But Danny's and Sandy's plates are completely full when they leave, and no one touches their food. Kenickie takes one bite of a burger on a different plate, but not nearly enough to empty it.

Krista

Continuity mistake: During the dance, there's one song where the guys stand in one line and the girls in another, and the couples take turns walking down the middle. In one shot, Danny is placing Sandy in line, and a couple (the woman has a blue dress on) is already starting down the middle. Then it cuts to another angle and no one is in the middle. Back to the first angle, and people are in the middle again.

Krista

Continuity mistake: When Marty is talking to Vince Fontaine before the dance contest, towards the end of their conversation she starts to lift up her purse with her right hand. But suddenly it cuts to another angle, and her arm is down.

Krista

Continuity mistake: During the dance contest, when Kenickie and Cha-Cha are dancing around like crazy (when she puts her foot up on his shoulder), you can see Danny and Sandy in the background, standing on the sidelines. Given that they're the last couple on the floor at the end, they should still be out dancing at this point.

Krista

Continuity mistake: In the middle of the dance contest, Patty Simcox does a funny front walkover, and comes dancing towards the camera. Over her shoulder, you can see Sonny running up behind her. But suddenly it cuts to another angle, and Kenickie is running up behind her to lift up her dress, and Sonny is nowhere to be seen.

Krista