Trivia: In the famous faked orgasm scene, the woman who says, "I'll have what she's having. . ." is Rob Reiner's mother.
Trivia: When they are in the museum and Harry says "For the rest of the day, we are going to talk like this...", the last thing he says is ad libbed. "But I would be proud to partake of your pecan pie." is not in the script. You can see Meg Ryan look off-camera at the director and say "Oh, no" but she continues with him. It's obvious that she wasn't expecting it. [This is confirmed as true in the documentary on the DVD.]
Trivia: The scene where they're all talking on the phone after Harry and Sally make love took approximately sixty takes.
Trivia: Joe is played by former President Gerald Ford's son, Steven. He very much resembles his father.
Trivia: Before Meg Ryan was cast as Sally Albright, Molly Ringwald was offered the role, but had to decline due to a busy schedule. Ringwald went on to play the part of Sally in 2004 in the stage version of the movie on London's West End.
Trivia: In one scene, Harry is reading "Misery" by Stephen King. The movie version of Misery was by the same director, Rob Reiner. (00:36:05)
Trivia: The off-camera voice that says "Hey everybody, 10 seconds until New Year" is that of the director, Rob Reiner.
Trivia: The now-famous "I'll have what she's having" line spoken by the lady in the diner was Billy Crystal's idea.
Trivia: The final interview at the end of the movie was completely improvised.
