Continuity mistake: When everyone is at the movies and Cherry throws her soda in Dally's face, he's dripping wet; you can see him blinking soda out of his eyes. A few lines of dialogue later, his face is completely dry, even though he didn't wipe it off with anything. It couldn't have dried so fast.
Continuity mistake: In the drive-in scene where Ponyboy and Cherry get up to get popcorn and soda, Ponyboy leaves with the popcorn Dallas gave him. They both purchase more popcorn and soda in the snack bar yet when they return to their seats, Ponyboy only has the popcorn he left with and Cherry has nothing.
Continuity mistake: When Ponyboy and Randy are talking, the camera keeps switching back to Two-bit making fun of the other Socs. When it does this you can see Ponyboy and Randy in the background. If you look carefully at Randy his arms are resting down the side of the car, but when the camera goes back to him as a close up his arms are resting on the roof of the car. This happens several times.
Continuity mistake: In the church when Ponyboy is reading Sodapop's letter, Dally is in the background with his left hand on his leg. When the shot switches to Dally, his hand is not on his leg, and he is lighting a cigarette. When the shot switches back to Ponyboy, Dally's hand is back on his leg.
Continuity mistake: In the scene where Two-Bit and Ponyboy are visiting Dally in the hospital, when Dally asks Two-Bit for his switchblade, he extends his right arm back for it, and his left arm is under the sheets. In the next shot, his left arm is extended backwards, even though there was no time to switch arms.