Continuity mistake: In the final New Year's Eve scene when Harry rushes into the party and sees Sally, her lipstick is very glossy and perfect. In the following shots of her, the lipstick is in various states of condition and sometimes slightly smeared, which evidently happened due to multiple takes.
Continuity mistake: After their first time having sex, Sally gets up to go get some water. When she comes back, she gets back in bed with Harry and settles herself with her head laying on his left pectoral. There is a quick change of shot, and suddenly her head is much higher, with her head laying on his left shoulder.
Continuity mistake: During the first car ride scene Harry is spitting the seeds out the window. One of the shots shown of the car from the outside shows the window still up after he has rolled it down.
Continuity mistake: When they are playing win, lose, or draw, Sally is trying to draw baby talk, and if you keep your eye on the drawing the baby looks different all the time and has eyes, and then doesn't have eyes, etc.
Continuity mistake: In the scene where Harry and Sally are having lunch in the diner (the orgasm scene), Harry's napkin is in his lap. You can see it when the camera angle is from the side showing both of them from the knees up. Every time that angle is used, the napkin is in a different place or altogether gone.
Continuity mistake: Coming out of the diner, on the trip from Chicago to New York, when Sally starts opening the door from the inside she does so with her right hand and the purse in her left hand. The next shot is from the outside and now she is pushing the door open using her left hand with the purse hanging from her left shoulder. (00:10:32)
Continuity mistake: The interior scene on the airplane shows a 707, with the lights mounted on distinctive boxes underneath the overhead bins. The airplane shown landing is a 737, which had the interior lights mounted flush.
Continuity mistake: In the deli scene when Sally is faking her orgasm, the camera movies to Harry. You can see the waiter approaching. When the scene is over, the waiter again approaches to take the order from the other woman (Rob Reiner's mom).
Continuity mistake: When Harry and Sally are at a restaurant having lunch (this is when she has the fake orgasm), if you look at Sally's sandwich when they show her from behind, you will see that where she has bit into the sandwich has changed. First the bite is on the right, then the middle, then the left, etc.
Continuity mistake: When Harry and Sally leave the diner on their trip from Chicago to New York, a blue Volkswagon pulls into the parking space next to them. During their dialog outside their car, the blue Volkswagon can be seen behind Sally in the first two shots, but is missing in the last shot of her.
Continuity mistake: When the three women are talking in the open air restaurant, just after Meg broke up with her boyfriend, check the background scenery. It alternates between very cloudy, sunny, and dim and bright, even though the time passed is only seconds.
Continuity mistake: When Harry and Sally are sitting at the table in the diner on their way to New York, Sally's hands change position several times. From the front they will be off the table, in the next shot taken from behind her, they are both on the table. This occurs several times.
Continuity mistake: Also on the trip, there's a conversation scene in the car, in which the camera flips back and forth from Billy to Meg as they chat/argue/flirt. Although the action/dialogue (and therefore the movement of the car) is continuous, the lock button on the driver's side door alternates between "up" and "down" with almost every camera cut.
Continuity mistake: When they stop at the little diner (on the trip to New York) Sally opens her menu twice.
Continuity mistake: When Harry and Sally are in the car driving to New York, in the front shots you see the car has no rear-view mirror.
Continuity mistake: During the fake orgasm scene, the bite on Harry's sandwich increases and decreases between shots.
Continuity mistake: When the couple exit the first diner they get in the car and start to talk. The stuff on the back seat changes between angles.
Continuity mistake: When the movie starts, Harry is kissing a woman while Sally waits in the car. A couple passes behind the car, but they disappear in the close-up.
Continuity mistake: When Harry and Sally are on their way from Chicago to New York, Sally's hair changes. You have to really look for it, but watch the curl in front appear and then disappear.
Continuity mistake: In the fake orgasm scene in the restaurant, when Meg Ryan holds her sandwich up there's one bite out of it, then it flicks on to Billy Crystal and when we see the sandwich again it has two bites out of it, but there was no time for her to have eaten any more. Later it has one bite again.
