The year is 1965 and a young couple is apartment shopping in New York City. Guy Woodhouse (the husband) is a struggling actor. The fact that Guy is a struggling actor later becomes a big theme in the movie. He is very obsessed with his work, often neglecting Rosemary. He desperately wants fame and fortune. His wife, Rosemary, is a homemaker. She is the innocence of the movie. She embodies the perfect example of a wife and mother. They take a tour of a large beautiful apartment building located in the center of the city. The city represents the modernness of the young couple and how young and vibrant they are. The apartment is for rent because the elderly woman that lived there died. During the tour the agent, Guy, and Rosemary notice peculiar things about the apartment. All her personal belongings, mainly plants and old writings, are still in there. The real state agent comes across a large dresser that seemed to be moved in front of a closet door. Guy and the agent move the dresser. They opened it and found only towels and a vacuum cleaner. All through the movie the closet is somewhat focused on. .
After the tour the couple is walking to a friend's house and discussing the apartment. Rosemary is very enthusiastic and wants to buy it. Guy is more hesitant, but agrees to buy it to make her happy. They arrive at their friend's house. His name is Hutch and is about 65 years old. During dinner he tells the couple all about the apartment complex's history with evil and witches. His first story is about a man that was accused of being a witch and holding satanic rituals in his apartment. Then he tells a story about a pair of sisters who cut and ate eight children in one of the apartments. Guy and Rosemary pass the stories off as just superstitious tales. .
The night before they moved in the couple have a midnight romantic dinner in the empty apartment. They make love on the living room floor. They suddenly hear a strange noise, and Guy cracks a joke about hearing the crazy child-eating sisters.