Rosemary's baby was born in June 1966 (6/66).
The book that Rosemary reads in the cab is the Book of Ceremonial Magic, by A.E. Waite, Chapter IV: The Rituals Of Black Magic: Section 4: The Grimoire of Honorius. The italic section has been entered into the natural flow of the text; the previous paragraph has been shortened to make space for it.
The Dakota Building on Manhattan's Upper West Side was renamed The Bramford for the film.
The devil costume that Anton LaVey was falsely rumored to have worn in the impregnation scene was later re-used in the film Asylum of Satan. A small woman had difficulty fitting into the tiny suit.
The last movie of special effects creator Farciot Edouart.
The movie's poster was as #21 of "The 25 Best Movie Posters Ever" by Premiere.
The script called for Rosemary (Mia Farrow) to explain to Guy (John Cassavetes), that she'd "been to Vidal Sassoon" for her dramatic new haircut. Thus, Vidal Sassoon was in fact flown to the set to arrange Mia Farrow's hair into the now iconic pixie cut she sports during the second half of the film. For the first part, she wears a blonde wig designed by famed stylist Sydney Guilaroff.
There is a heatedly disputed rumor that Sharon Tate appears unbilled at the party Rosemary gives for her "young" friends.
There is a popular rumor that Church of Satan founder Anton LaVey gave technical advice and portrayed Satan in the impregnation scene. This is false - LaVey had no involvement with the film.
There was a popular belief that Alfred Hitchcock was originally offered the chance to direct this movie. This has been deemed false. The director was never approached.
This film, along with Repulsion and Le locataire, forms a loose trilogy by Roman Polanski about the horrors of apartment/city dwelling.
This was Roman Polanski's first American film. His first American film was going to be Downhill Racer, but Robert Evans of Paramount decided that "Rosemary's Baby" would be more suited to Polanski.
This was Roman Polanski's very first adaptation, and it is very faithful to the novel. Pieces of dialog, color schemes and clothes are taken verbatim.
When Rosemary receives the book "All of Them Witches," she is told that 'the name is an anagram.' At first she tries to rearrange the letters of the book's title, but then realizes that the clue referred to a name within the book. However, the title actually is an anagram for 'Hell a Cometh Swift.'