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.
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