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 Nick Nolte confronts his daughter in her bedroom about meeting with Robert De Niro, as the camera angle switches from Nolte's face to his daughter's face, his hand over her mouth changes positions.
Continuity mistake: When De Niro kisses Juliette Lewis, the positions of their heads reverse twice as the camera angle changes.
Continuity mistake: When the Bowdens are eating dinner on their boat at Cape Fear, the wine glass that Lee is holding changes position and her grip on the glass changes throughout shots.
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.
Visible crew/equipment: When Robert De Niro is smoking a cigar at the cinema, you can quite clearly see someone puffing and blowing cigar smoke from behind his seat to give the appearance of lots of hazy smoke.
Factual error: 'Cape Fear' is based in North Carolina, and cars shown in the film have North Carolina license plates. However, the cars have plates on both the front and back, and in North Carolina, cars only have plates on the back.
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.