She is remembered for playing the title character in the cult film Candy where she appeared with John Huston, Ringo Starr, Walter Matthau, James Coburn, Richard Burton and Marlon Brando.

[1] Aulin's success as Miss Teen International attracted attention not only in Sweden, where she appeared on the popular entertainment show Hylands hörna, but also in Italy, and in 1967, at age 16, she made her feature-film debut with a supporting role in the comedy Don Giovanni in Sicilia (Don Juan in Sicily), based on the novel by Vitaliano Brancati.

This film led to a movie career for Aulin that would last a little more than six years, starting with leading roles in two giallo films: the pop art-style Col cuore in gola (With Heart in Mouth, 1967) directed by Tinto Brass, and the avant-garde La morte ha fatto l'uovo (Death Laid an Egg, 1968) directed by Giulio Questi.

In late 1967, Aulin was cast as the title character in her most famous film, the American-Italian-French co-production Candy, directed by Christian Marquand.

The story involves Aulin's character's search for the meaning of life, which leads to encounters with a variety of different men and always ends in a sexual situation.

She played an undead avenging angel in Joe D'Amato's gothic horror film La morte ha sorriso all'assassino (Death Smiles on a Murderer, 1973) and also appeared in the thriller Una vita lunga un giorno (Long Lasting Days, 1973).