Campanini was known for his association with French opera, and introduced numerous works to the United States; these included Hérodiade, I gioielli della Madonna, Louise, Pelléas et Mélisande, Monna Vanna, Jules Massenet's Sapho, and Thaïs.
A highly versatile singer, he also appeared in the title roles of La Monnaie's productions of Hamlet, Rigoletto, Hérodiade, and Le roi Arthus, as well as singing Count di Luna in Il trovatore, Iago in Otello, and Baron Scarpia in Tosca.