Sällström made her first stage appearance in Hudiksvall at the age of 15, in A Midsummer Night's Dream. She became famous in Sweden in the 1990s, after portraying the teenage girl Victoria Bärnsten in the soap opera Tre kronor. Thereafter, she appeared in numerous productions, and received a Guldbagge Award for Best Actress in a Leading Role for the 1997 film Under ytan. Later that same year, unable to cope with her new-found Celebrity, she took a break from filming and moved to Copenhagen, where she worked in a café.
Sällström married Albin Sällström in 2000; they were divorced in 2002, about a year after the birth of their daughter Talulah. In 2004, Sällström and Talulah experienced the 2004 tsunami while vacationing in Thailand.
Sällström was found dead in her Malmö home on February 13, 2007, from an overdose of sleeping pills She had recently been released from a psychiatric unit where she had been receiving treatment for depression. Her lifelong struggle with depression was exacerbated by her experience in Thailand. In a 2006 interview with the Editor of the magazine Tove, she said, "I always thought I would be dead by the age of 30."
