Born in Palermo, Dominici became best known for his many villainous roles in horror and fantasy films. He is possibly most famous for his performance as the monstrous Igor Javuto in Mario Bava's Black Sunday (1960). His filmography includes more than 80 titles, including Antonio Margheriti's Castle of Blood (1964), in which he appeared with Black Sunday star Barbara Steele. Dominici dubbed the voice of German actor Walter Ladengast in Werner Herzog's Nosferatu the Vampyre (1979).
Dominici's daughter, Germana, is an Italian stage actress; at the age of 14 she had a small role in Black Sunday.