The cool, elegantly beautiful blonde Dahlbeck appeared in films by Gustaf Molander and others from 1942, switching from comedy to drama with apparent ease. A gifted and versatile performer, Dahlbeck gave a landmark performance, spanning from girlish naivete to middle-aged despair, in Alf Sjoberg's powerful tale of a long-suffering rural woman, "Only a Woman" (1949). Outside of Sweden, however, she is perhaps best-known for her finely controlled performances in several Ingmar Bergman films. Her first with the director was "Kvinnors vantan/The Secrets of Women" (released in Sweden in 1952; in the USA in 1961). Although made during Bergman's most fruitful dark period, the film is a light-hearted comedy with Dahlbeck as the other woman in one of the episodes. Dahlbeck is also recalled as Desiree, the actress and former mistress of a lawyer, in Bergman's comedy "Smiles of a Summer Night" (1955). She received the Best Actress award at the 1958 Cannes Film Festival for her turn as a woman coping with a miscarriage in Bergman's poignant "Brink of Life".
Dahlbeck was a wife watching her husband scheme against Patrick O'Neal in John Cromwell's American-Swedish production "A Matter of Morals" (1960) and was William Holden's wife who rejects him when she assumes he is a spy in "Counterfeit Traitor" (1962). She has also written plays, screenplays, novels and a volume of poetry, "Genom Fonstren" (1963), under the nom de plume Lis Edvardson. Dahlbeck's major screenplay credit was "Woman of Darkness"/Yngsjormordet" (1966), about the last woman executed in Sweden. She stopped working actively in films in 1970.