The orgasm scene was filmed at Katz's Deli, an actual restaurant on New York's E. Houston Street. The table at which the scene was filmed now has a plaque on it that reads, "Where Harry met Sally...hope you have what she had!"
In the museum scene, Billy Crystal (Harry) ad-libbed, "But, I would be proud to partake of your pecan pie." Meg Ryan (Sally) laughed and looked to her right where director Rob Reiner silently prompted her to go with it.
Director Rob Reiner, screenwriter Nora Ephron, and producer Andrew Scheinman chose beautiful locations to highlight the characters' lack of insight. Harry and Sally are as blind to romance as they are to the love growing between them. The same logic was used for Harry's apartment. The windows overlook the Empire State Building; it could either the loveliest, or loneliest, view in the world.
The concept of Sally being a picky eater was based on the film's screenwriter, Nora Ephron. Years after the movie came out, when Ephron was on a plane and ordered something very precise, the stewardess looked at her and asked, "Have you ever seen the movie When Harry Met Sally... (1989)?"
Sally's picky and crazy eating habits were put into the movie after director Rob Reiner saw screenwriter Nora Ephron ordering her food, in the same way Sally does in the film. When Reiner brought this up, Ephron stated, "I just want it the way I want it," a line which was put into the movie.
In an interview with National Public Radio on November 2, 2004, screenwriter Nora Ephron credited Meg Ryan not only with the idea of faking an orgasm in the famous restaurant scene, but also with the idea of setting it in a restaurant in the first place.
For the infamous orgasm scene, the original script called for Harry and Sally to merely talk about women faking an orgasm, until Meg Ryan suggested that Sally actually fake an orgasm at the table. Director Rob Reiner loved the idea and put it into the script.
Before deciding on the title, "When Harry Met Sally...," screenwriter Nora Ephron, producer Andrew Scheinman, and director Rob Reiner considered: "Just Friends," "Playing Melancholy Baby," "Boy Meets Girl," "Blue Moon," "Words of Love," "It Had To Be You," "Harry, This Is Sally," and "How They Met."
The quote, "I'll have what she's having," was not only voted #33 on the AFI's list of "Best 100 Movie Quotes in American Film," as well as the only quote on the list to be spoken by a non-professional actor (Rob Reiner's mother delivered the line), but it was also the only film dialogue on the list ever uttered by the actor who delivered it.
The character of Harry was somewhat based on director Rob Reiner. Reiner was depressed, and loved being depressed, like Harry Burns in the film. The character of Sally was somewhat based on screenwriter Nora Ephron. Ephron was optimistic, cheerful, loved control, and was the type of person who was "just fine" with everything, like Sally Albright.
During the ending scene, Harry mentions never understanding what the song "Auld Lang Syne" was about. Some years earlier, director Rob Reiner also questioned the meaning of the song when portraying Mike Stivic on an episode of All in the Family (1971).
While writing the script, director Rob Reiner once said, "You know how women have a base of make-up? I have a base of depression. Sometimes I sink below it. Sometimes I rise above it." Since the character of Harry Burns was based on the depressed Reiner, screenwriter Nora Ephron threw the line into the script, which Reiner cut somewhere along the line.
Molly Ringwald was offered the role of Sally Albright, but was forced to decline due to a busy schedule. She would later go on to play the character in 2004 in the stage version of the film, on London's West End.
In many romantic comedies, there is a bullying significant other or a contrived misunderstanding that would keep the two leads apart. This film is special in that it has neither of these clichés; the only thing keeping Harry and Sally apart is their own various neuroses.
Nora Ephron supplied the structure of the film with much of the dialogue based on the real-life friendship between Rob Reiner and Billy Crystal. For example, in the scene where Sally and Harry appear on a split screen, talking on the telephone while watching their respective television sets, channel surfing, was something that Crystal and Reiner did every night.
When posed the film's central question, can men and women just be friends, Meg Ryan replied, "Yes, men and women can just be friends. I have a lot of platonic (male) friends, and sex doesn't get in the way." Billy Crystal said, "I'm a little more optimistic than Harry. But I think it is difficult. Men basically act like stray dogs in front of a supermarket. I do have platonic (women) friends, but not best, best, best friends."
The football game scene uses footage from an actual New York Giants game. However, the long range crowd shots are of a Buffalo Bills home game at Rich Stadium. It had the same colors on the fans but a more spirited version of "the wave."
The split-screens were an homage to Pillow Talk (1959). In those days, the Hays Code set moral guidelines for all the films released by major studios. Movies weren't allowed to show a couple in bed (or bath or beyond) together, or any sort of sexual relationship between unmarried partners. (The code was abandoned in 1968.) Harry and Sally were kept apart to show how close they were as "just friends."
When Harry realizes he wants to see Sally on New Year's Eve, he is near Washington Square Park. The party where Sally is attending is at the Puck Bulding, 295 W Lafayette Street, about a half mile away via Bleecker Street. If Harry runs five mph, he would have a six-minute run before arriving at the party.