1. John Hughes wrote the role of Samantha Baker with Molly Ringwald in mind. After he received a headshot of her it inspired him to write the movie.
2. Hughes wrote the film over a weekend.
3. The movie also marked Hughes' directorial debut.
4. Hughes was so impressed with Anthony Michael Hall's performance in National Lampoon's Vacation (a film that Hughes wrote), that he created the role of Ted “The Geek” with him in mind.
5. Viggo Mortensen was almost cast as Jake Ryan.
6. Michael Schoeffling (Jake Ryan) was so shy during his audition that he almost lost the role. But the film’s producer Michelle Manning found him so “stunning and dreamy” that they cast him.
7. Ages of the cast when the movie was being filmed:
8. Gedde Watanabe, who played Long Duk Dong, was 28.
9. The dress that Ringwald wears to the school dance was supposed to be worn by Liane Curtis (who played Randy). But when Ringwald saw it she asked to wear it.
10. The license plate number on Jake's car "21850" is actually Hughes' birthday -- February 18, 1950.
11. Jimmy Iovine, the future co-founder and head of Interscope Records, was the movie’s music supervisor.
12. They didn’t have the budget to air-condition the gym during the school dance scene -- it was over 100 degrees during filming.
13. This was the second movie both Joan and John Cusack co-starred in.
The siblings have co-starred in nine other movies together:
Class (1983), Grandview, U.S.A. (1984), Broadcast News (1987), Say Anything... (1989), Grosse Pointe Blank (1997), Cradle Will Rock (1999), High Fidelity (2000), Martian Child (2007), and War, Inc. (2008).