Continuity mistake: When Jules is leaning against Michael's hotel door she is smoking a cigarette. When he opens the door she falls back and ash from the cigarette falls on her hair. Two shots later it is gone and her hair is rearranged while she is still on the floor. Then the ash reappears a few shots later.
Continuity mistake: Toward the end of the movie, Jules is yelling for Kimmy in a public restroom. When she walks in, her curls in the back of her hair are loose. Another shot shows her curls tight, and later they are back loose again. This actually happens repeatedly throughout the movie. With Jules's long, curly hair, it's obvious when it changes.
Continuity mistake: Jules and Michael are looking for Kimmy at the train station. Michael is sitting at a bench and Jules comes to him. Behind you can see two train employees walking, one of them is pulling a small metal suitcase. Ten seconds later, as Jules is standing at Michael's side, the same employees are walking behind them.
Continuity mistake: When Jules goes into Kimmy's dad's office, she sits down at his desk and immediately starts typing an email. After sitting back down from falling off of the chair, the box that the wedding ring is in suddenly appears on top of some papers, which she later sets aside. She didn't take it out of her pocket during the time she was sitting or after getting back up.
Continuity mistake: When Jules is in the dressing room, and Michael comes in, she grabs her jacket to cover herself up. In the first couple of shots of her, her jacket is almost folded in half. In the very last shot, it's not folded. She didn't have any time to unfold the jacket during the last two shots.