Continuity mistake: When George takes her to the airport (in NYC), they are at O'Hare. Later, when she gets off the plane, she's still at O'Hare.
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: At the brunch the morning of Kimmy and Michael's wedding, Jules' eyeliner under her bottom lashes is darker and more defined than in the very next shot taken. Her make-up is lighter and more natural looking immediately in the next scene.
Continuity mistake: If Jules flew into O'Hare, Kimmy would not have to drive (at all) on Lake Shore Drive to get downtown. In that scene they are going North on LSD, the next cut, south (you can tell from the side the lake is on, or they reversed the film).
Continuity mistake: When Jules sits outside of the hotel room and lights a cigarette, the next quick shot shows the cigarette over halfway burned down. She couldn't have possibly smoked that much in one puff.
Continuity mistake: In the scene where Jules and Kimmy are eating in a restaurant together, in one scene, Kimmy's necklace is tucked into her dress, in the next cut it's untucked, and when the camera finally cuts back to her, it's tucked in again.
Continuity mistake: Michael opens the door while she's leaning against it, and while she has a cigarette in her left hand. When she falls onto the floor of the room with no solid object to lean against, the cigarette is in her right hand. (01:07:50)
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. (01:23:20)
Continuity mistake: When Jules is trying on her dress, she's wearing a white bra with a visible strap. Later, this becomes a black bra.
Continuity mistake: In the scene where Jules is leaning against the door smoking a cigarette, the cigarette continually changes length. At the end of her conversation with the porter, she has almost finished it, yet in the next shot, half of it still remains.
Continuity mistake: In the Karaoke bar, when Kimmy is near the beginning of her song, the close-up of Michael shows him starting to smile. The next shot from further away shows him totally into the song, nodding his head and then the next shot, up-close, he is back to starting to smile.
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. (00:58:35 - 01:00:20)
Continuity mistake: When Jules in in the bed room in her bra and undies Michael walks in and she pulls the cover around her and part of it is folded over. In the next shot it is all straight and nothing is folded over, which she wouldn't have had time to do.
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. (00:14:40 - 00:15:15)
Continuity mistake: In the scene where Jules is typing the email to Mike's boss, there is a picture of Kimmy on the desk. The camera changes angles and when it comes back the picture is gone. (00:58:50)
Continuity mistake: In the gazebo scene when Jules is confessing to Michael that she loves him and for him to choose her, pick her, a strand of hair keeps appearing and disappearing from her forehead.
Factual error: Rupert is driving Julia to the airport but the road signs for I-90 and Mannheim Road are at Ohare airport. She seems to leave from Ohare and arrive at Ohare. (00:10:08)