The brilliance of the film comes more from Polanski's direction, and from a series of genuinely inspired performances, than from the original story.
Rosemary’s Baby is one of horror cinema’s all-time slow burns, drawing viewers gradually into entertaining the possibility that the movie’s series of strange coincidences and accumulating sense of dread are only subjective representations of Rosemary’s unraveling mental state.
The A.V. Club
As Polanski leads the audience step-by-step through Levin’s queasy plot, he pushes them toward a conclusion straight out of a Louvin Brothers gospel song. Oh yes, brethren: Satan is real.
This is horror rooted not in misty Carpathian castles, but in recognisable modern life, with the satanists depicted not as outlandish fiends but the sort of everyday folk you might encounter on any urban street.
Time Out London
A supremely intelligent and convincing adaptation of Ira Levin's Satanist thriller.
A very sophisticated, very effective piece of work spun from primal images, with an excellent cast.
TV Guide Magazine
Truly frightening because so much of it is so plausible, ROSEMARY'S BABY is one of the finest examples of modern horror, a milestone in the evolution of the genre. Although the subject matter is ultimately supernatural, the treatment is very realistic.
New York Daily News
Polanski’s direction is smooth and the film itself happily understated. The tension created is practically unbearable.
It's that smile playing on Rosemary's lips, suggesting that her maternal instinct and the conspirators' hold on this vapid baby doll have prevailed, that provides the biggest chill.
The New York Times
Miss Farrow is quite marvelous, pale, suffering, almost constantly on-screen in a difficult role that requires her to be learning for almost two hours what the audience has guessed from the start...Everyone else is fine, but the movie—although it is pleasant—doesn't quite work on any of its dark or powerful terms.