Continuity mistake: When De Niro first meets Nolte's lady-friend, they are having a conversation in a bar or restaurant. As the camera goes from De Niro to the woman, the woman's top blouse button is open in one shot, then closed, then open, etc.
Continuity mistake: When Sam is talking to the P.I about "Taking care of Max," he gets into his car and the window is up. A few seconds later, the window is down. There wasn't enough time for him to roll it down.
Continuity mistake: When Sam Bowden is talking to Max Cady at the restaurant, Max is secretly taping the conversation. When it is played back in the courtroom after Max's beating, how the conversation is delivered and some of the words differ from what was said before.
Continuity mistake: When Max Cady calls Dani on the phone imitating her Drama teacher, Dani takes out her retainer and places it on the bedside table. After that, her retainer keeps jumping from the bedside table to back in her mouth for the next several minutes until she finally puts it back in when she hangs the phone up.
Audio problem: When Claude Kersek is garroted by Max Cady, the 'strangling' sound effect is heard right before the piano wire goes around his neck, and then again when it does.