After his retirement from the stage in 1998 he continued to perform and record, most often with his second wife, pianist Christina Petrowska Quilico, CM OOnt FRSC, with whom he made four CDs.

Years later, in 1970, he sang the role of Nottingham in the Tito Capobianco production of Roberto Devereux opposite Beverly Sills, Plácido Domingo and Susanne Marsee.

On the international scene, Quilico made his debut in 1959 at the Spoleto Festival in the title role of Donizetti's "Il duca d'Alba."

He made his debut at Covent Garden in London in La traviata opposite Dame Joan Sutherland in 1960, and remained a member of that company until 1963.

In Canada, Quilico performed regularly with the Canadian Opera Company in Toronto, debut as Iago in Otello in 1960; later roles were Rigoletto, Macbeth, Simon Boccanegra, Germont, Amonasro in Aïda, Scarpia in Tosca, Enrico in Lucia di Lammermoor, etc.

Throughout the 1970s he performed in various centres in the United States, including San Francisco (Luisa Miller), Philadelphia (I puritani), New Orleans (Manon), Baltimore (Tosca).

In 1972 he sang the title role in the Opera Orchestra of New York's concert performance of Gioachino Rossini's William Tell with Klara Barlow as Mathilde.

[3] Quilico reached the Metropolitan Opera in February 1972 when he replaced at short notice the scheduled Golaud (Thomas Stewart) in Pelléas et Mélisande.

The couple toured extensively in duo concerts and collaborated on his biography, Mr. Rigoletto: In Conversation with Louis Quilico and filmed a teaching video for York University.