1. The film's producer, William Castle, bought the movie rights before the book was even published.
2. Ira Levin, the book's author, named the apartment building The Bramford, after Dracula author Bram Stoker.
3. It was Polish director Roman Polanski's American film debut.
4. Polanski originally wanted actress Tuesday Weld for the role of Rosemary.
5. Then-Paramount studio head Robert Evans — who wanted a bigger name for the role of Rosemary — suggested Mia Farrow (center), who at the time was appearing on the very popular TV show Peyton Place.
6. Robert Redford, Warren Beatty, and Jack Nicholson were all sought after for the role of Guy Woodhouse, Rosemary's husband.
Redford was the first choice, but turned down the role. While Nicholson actually tested for it.
Source: TCM
7. During filming, Farrow created a chart to keep track of everyone who was nice and mean to her. In response Polanski created one just for her.
Source: Mia and Roman
8. Farrow sang the lullaby over the film's opening credits:
View this video on YouTube
9. Contrary to popular belief, Vidal Sassoon did not actually create Farrow’s short pixie haircut.
Farrow addressed this rumor on Twitter in 2012, after the death of Sassoon.
Ppl ask: Vidal Sassoon trimmed my inch long hair as publicity prank 4 RosemrysBaby Actually I cut my own hair 2yrs earlier. He was nice. RIP
mia farrow
@MiaFarrow
Ppl ask: Vidal Sassoon trimmed my inch long hair as publicity prank 4 RosemrysBaby
Actually I cut my own hair 2yrs earlier. He was nice. RIP
10. The long hair Farrow had in the film was actually a wig.
11. At the time of filming, Farrow was actually a very strict vegetarian, but for the scene in which Rosemary is hungry, Polanski asked her to eat raw liver — which took several takes.
12. Iconic silver screen legend Joan Crawford had her cameo cut from the film.
13. In the scene where Rosemary calls Donald Baumgart — the actor who mysteriously goes blind and is replaced by Guy — the voice heard on the other end is actor Tony Curtis.
14. The scene where Rosemary walks into traffic was spontaneous and genuine. Polanski told Farrow, "Nobody will hit a pregnant woman."
15. Frank Sinatra's lawyer served Farrow with divorce papers while she was on the set, in front of cast and crew.
16. A year after the movie opened, Polanski's wife, Sharon Tate, was brutally murdered by Charles Manson's followers. The murder created a myth that the film was cursed.
17. In 1976, a TV movie sequel was made, Look What's Happened to Rosemary's Baby, and starred Patty Duke in the role of Rosemary.
18. In 1997, 30 years after Rosemary's Baby was published, Levin wrote a sequel, Son of Rosemary. The book also had nothing to do with the 1976 sequel.
