Rocca was born and raised in Acireale, a small town near Catania. She became Miss Catania in 1953, and was discovered by talent scouts after competing in a Miss Italy competition.
Rocca made her film debut in French director Maurice Cloche'sMarchands 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. Rocca fell in love with Germi during filming and attempted suicide when he rejected her. After that, she was considered unstable and was not offered significant roles. A nervous breakdown led to a stay in a mental hospital.
After playing minor roles in movies and television, her show business career ended in 1967. She ended her days in a retirement home in Milo, near Catania. 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.
