She trained at the Staatliche Schauspielschule, earning her diploma at age 19, and then worked at several provincial theatres in the former East Germany.

[1] She made her national and international breakthrough as Tilli in Bis daß der Tod euch scheidet [de] in 1979, directed by Heiner Carow, portraying a woman's best friend in a film about violence in a young marriage.

Krößner appeared in the title role of the DEFA film Solo Sunny in 1980, written by Wolfgang Kohlhaase and directed by Konrad Wolf, and remained identified with this role of a young woman from Prenzlauer Berg, a factory worker who dreams of artistic freedom as a singer,[2] touring with a mediocre band, and in conflict with social conventions of the period.

[2][3] For her character role, she was awarded the Silver Bear for Best Actress at the 30th Berlin International Film Festival.

[5] In 1985, Krößner and her husband, the actor Bernd Stegemann [de], moved to West Berlin where she played on stage, with guest performances.