Rocca made her film debut in French director Maurice Cloche's Marchands de Filles (1957) and also appeared in the Riccardo Freda film Caltiki – The Immortal Monster (Caltiki – il mostro immortale, 1959), and Esther and the King (1960).

More film roles followed, but Rocca did not garner international attention until Divorce, Italian Style (Divorzio all'Italiana, 1961).

Rocca became a star after playing the part of the smothering wife Marcello Mastroianni is desperate to escape in Pietro Germi's international box-office hit.

After playing minor roles in movies and television, her show business career ended in 1967.

There she wrote four books: Agente segreto con licenza di vivere; Avvocato offresi; Il condannato a morte; and Psicoanalisi, sogni, fantasie nascosti nella mente; and a collection of poems, Ara.