She was born as a fisherman's daughter in Sollefteå, Ångermanland in northern Sweden. She took ballet lessons as a girl and was accepted by the Stockholm Royal Dramatic Theatre's School in 1948. For years she worked with Swedish director Ingmar Bergman, where she developed her personal style, acting with neurotic intensity like in The Silence (1963) or Cries and Whispers (1972), making her the third actress of world fame coming from Sweden (after Greta Garbo and Ingrid Bergman).

She shared the best actress award at the 1958 Cannes Film Festival and received a Guldbagge Award as best actress in 1964, the first year the award was given out, for her performance in The Silence.

She was married to Harry Schein, the founder of the Swedish Film Institute, for more than 30 years until 1989, although they had lived separately for many years before the divorce.

In her later years she lived in Rome, Italy. She returned to Sweden for medical treatment and later died from cancer in Stockholm, Sweden, 20 days short of her 78th birthday.