Trempont attained an international career with performances at the Opéra-Comique in Paris, where he made his debut in 1966, and sang (French versions) Figaro in the Mozart opera and in Rossini's; Marcello, Sharpless, Gaillardin (Gabriel von Eisenstein) in Die Fledermaus (La Chauve-Souris), Rimbaud in Le comte Ory, Zurga in les pêcheurs de perles and le Marquis de Clainvillela in Sauguet's La Gageure imprévue. He appeared at the Festival d'Aix-en-Provence, the Royal Opera House London, La Scala, Milan, La Fenice, Venice, Teatro San Carlo in Naples and San Francisco Opera.