Zetterlund began by learning the classic jazz songs from radio and records, initially not knowing the language and what they sang about in English. Her hit songs included "Sakta vi gå genom stan" (Swedish cover of "Walking My Baby Back Home"; in Swedish a tribute to Stockholm town), "Visa från Utanmyra", "Sista jäntan", "Trubbel", "Gröna små äpplen" ("Little Green Apples"), "Monicas vals" ("Waltz for Debby"), "Stick iväg, Jack!" ("Hit the Road Jack"), "Att angöra en brygga", "Var blev ni av", "Måne över Stureplan" (cover of Sting's "Moon Over Bourbon Street") and "Under vinrankan!", among many, many others.
She also interpreted the works of such Swedish singer-songwriters as Evert Taube, Olle Adolphson and Povel Ramel, and all through her life interpreted the works of international and American jazz musicians/songwriters. She worked with some of the greatest international jazz names including Louis Armstrong, Bill Evans, Stan Getz, Steve Kuhn and Quincy Jones, and in the Scandinavian jazz world with people like Georg Riedel, Egil Johansen, Arne Domnérus, Svend Asmussen and Jan Johansson.
In 1964, she recorded the critically acclaimed jazz album Waltz for Debby with Bill Evans, a record she herself described as "the best I've done"[citation needed] and was the most proud of. Her professional skill was amply demonstrated in this album in performing the challenging Harold Arlen song, "So Long, Big Time".
Her long career also included the song "En gång i Stockholm" ("Winter City"); a jazz ballad with which she represented Sweden in the 1963 Eurovision Song Contest. She finished last, however (mainly because the song genre was not suitable for the competition)[citation needed] and scored the infamous nul points, but still managed to remain successful in Sweden. Her collaboration with the comic duo Hasse & Tage (in the 1960s and 1970s) eventually led to a stage career in revues and films. Memorable are her parts in films Att angöra en brygga and Äppelkriget, with her most memorable role being in Jan Troell's Utvandrarna (aka The Emigrants; with Liv Ullmann and Max von Sydow in the leads) as Ulrika, a former prostitute who together with her teenage daughter Elin (portrayed by Zetterlund's daughter, Eva Lena Zetterlund) join the main characters in their emigration to America in the 1850s, a role for which Zetterlund received a Guldbagge Award for Best Supporting Actress. She appeared in more than 20 films and television series throughout her life.
