Continuity mistake: When the brunette is in the shower and that boy shows up he is wearing brown pants, but when you see the clothes lying on the carpet while they are in bed together, the pants are blue jeans.
Continuity mistake: When Julie and Stacy are getting ready for the party, Stacy is helping Julie with the buttons on her sleeves. Stacy buttons the right sleeve, then the left in one shot, and in the next shot Stacy is buttoning Julie's right sleeve again.
Continuity mistake: At the "valley party" near the beginning (the one where Julie and Randy meet) you can clearly see "x's" marking the floor where the actors are dancing, just so they are sure to hit their marks.
Continuity mistake: In the scene in the diner Julie's friends are telling her Tommy wants to take her back, Stacey enters with school books close to chest and sits down. The next shot shows the books on the table, and the following shot shows books back against her chest.
Continuity mistake: In the sleepover scene in Suzi's bedroom, the girls are dancing, and Stacey is wearing plain, light blue underwear. As they cross into Suzi's mother's bedroom, Stacy's underwear change into striped underwear.