She first appeared in a movie directed by her father in 1978, entitled Sweet Home. Bergström embarked on a film career in 1982, working in the television mini-series “Time Out”. A year later she appeared in the satirical comedy series Vidöppet, or Wide Open in English. In 1988, she graduated from “Teaterhögskolan”, the theatre academy, in Stockholm, after which she worked at the Royal Dramatic Theatre (Dramaten) and at the Stockholm City Theatre.

With Tove Alsterdal, a playwright and journalist, she wrote her first screenplay, Så olika (2009), or So Different in English. She first directed Mind the Gap , which was released in 2007. In 2015, she directed her fourth film, A wonderful fucking Christmas! Not the original screenwriter.  She is also a singer, singing more than 100 songs of Édith Piaf at the City Theatre. In 2002, she recorded an album of Piaf songs.

In 2008, she starred in a drama about Nobel Prize-winning author Selma Lagerlöf. She is known for her work in films, such as Miss Julie and House of Angels. The Woman on the Roof is described as the role that made her a noted actress. Although it was not a box office success, it was praised by the film critics. She became more notable after her “vivid portrayal of a tough city girl” during World War II in 1939. In 1990, she received the Swedish Film Academy Kurt Linder prize and in 1992 Teaterförbundet Daniel Engdahl scholarship.