 After his ordination he did pastoral work in Venice, and also worked in the offices of the patriarchal curia.Pope Pius X, Patriarch of Venice until his election as Pope, soon appointed Cavallari titular bishop of "Philadelphia", and auxiliary bishop of Venice on 22 August 1903 and had him consecrated the next day in Rome by Cardinal Francesco Satolli.While the search for a new Patriarch was ongoing, Cavallari was named vicar general of Venice in January 1904.