New York City, fall of 1965: In the bustling heart of Manhattan, young newlyweds Rosemary and Guy Woodhouse (Mia Farrow](/actor/mia-farrow) and John Cassavetes) find a new beginning as they rent an apartment in the gothic elegance of the Bramford building. Despite their friend and landlord, Edward "Hutch" Hutchins (Maurice Evans), warning them about the building's dark history—one that includes cannibal killers, Satanists, and notorious witches like the Trench Sisters and the infamous Adrian Marcato, who, back in the late 1890s, ignited a scandal by claiming he could summon "The Living Devil"—the couple chooses to ignore the warnings and move in anyway.
As the aspiring actor Guy strives for more significant roles beyond his small TV parts and commercials, Rosemary, a kind-hearted soul from Omaha, Nebraska, is committed to supporting him. She's estranged from her family, who disapprove of her marriage, feeling isolated in the vast city. Life as a devoted housewife fills her existence, yet Rosemary finds herself longing for deeper connections, often feeling sweetly naïve and lonely amidst a good circle of friends.
Their lives take a jarring turn when Rosemary befriends Terry Gionnoffrio (Victoria Vetri), a young woman rescued from addiction by the eccentric elderly couple, Roman and Minnie Castevet (Sidney Blackmer and Ruth Gordon). However, after a tragic accident leads to Terry plunging to her death, Rosemary finds herself increasingly entwined with the Castevets, who seem overly interested in her and Guy's lives. This odd relationship grows tense as Rosemary notices unsettling shifts in Guy, who unexpectedly leaps to success just as his rival, Donald Baumgart, mysteriously goes blind.
Then, in a surprising twist, Guy expresses his desire to start a family. Overjoyed, Rosemary prepares for "baby night," during which she receives a strange chocolate mousse from Minnie. Although Rosemary finds it unpleasant, Guy dismisses her concerns, leading her to eat it anyway. Soon after, she experiences a disorienting night filled with haunting dreams—a surreal sequence that transports her to bizarre places, culminating in a horrifying event where she feels violated, awakening sore and confused.
As the months roll on and Rosemary becomes pregnant, her joy is overshadowed by persistent dread and doubts about those around her. With Dr. C.C. Hill (Charles Grodin) confirming her pregnancy, she finds herself under the dubious care of Dr. Abraham Sapirstein (Ralph Bellamy), who prescribes strange herbal remedies from Minnie and fails to address her growing health concerns. Ignoring her pain, those close to her—especially the Castevets—seem more interested in her condition than her well-being, which disturbs her deeply.
In an effort to regain some sense of normalcy, she throws a party for her friends but is met with concern over her worsening state. Rosemary's fears escalate when her friend Hutch visits, only to mysteriously fall into a coma and die shortly after. Inheriting his final gift, a book titled "All of Them Witches," provides her with a confusing but chilling insight into her predicament. Unraveling the puzzle leads to a horrifying realization—her suspicions that Roman and Minnie are part of a malevolent coven take hold.
As Rosemary plunges deeper into her conspiracy, her life spirals into a nightmare. When she realizes Guy may have sacrificed their baby to aid his career, her attempts to seek help are thwarted, leading to forced confinement by those she once trusted. Eventually, she awakens to a sinister revelation: her child, delivered under false pretenses, is tied to dark forces. Discovering the chilling truth about the coven and their intentions, Rosemary faces the ultimate test of motherhood.
In a desperate bid, she confronts the Castevets and their coven, revealing her maternal instincts. Torn between horror and the primal bond with her child, she cautiously approaches the bassinet, resisting the darkness that surrounds her. With her heart conflicted, she begins to sing to her baby, signaling a moment of acceptance amidst the chaos that threatens to engulf her life.
