Continuity mistake: Lolita goes into Humbert's room and she is chewing gum. She then sits on Humbert's lap and sticks her gum on a piece of paper on his desk. A couple of shots later, she is chewing gum again.
Continuity mistake: Just before Charlotte Haze gets hit by a car, when Humbert is preparing the drinks, the glasses are two thirds full. However, when he answers the phone, the glasses are only half full.