Shortly afterwards, however, his interest in the theatre lured him away from his post in a local law firm, and he first starred on the stage in 1949 opposite Paulina Singerman in Antonio Cunill Cabanellas' Fin de semana (Weekend).

[3] These roles in film and theatre earned Marzio a fellowship to Lee Strasberg's prestigious New York City drama school, the Actors Studio, in 1960.

Marzio returned to film in Raúl de la Torre 1986 period piece, Pobre mariposa (Poor Butterfly), and starred with American actor Don Stroud in a 1988 U.S.-Argentine production, Two to Tango.

A 1992 adaptation of Albert Camus's The Plague (directed by Luis Puenzo) also included the steely-eyed Marzio, and also worked with French actress Dominique Sanda and Federico Luppi in Edgardo Cozarinsky's Guerriers et captives (Warriors and Prisoners).

Alejandro Doria directed Marzio in the 2006 historical drama, Las manos (The Hands) and musician/filmmaker Fito Páez cast him as the dictator in his satirical ¿De quién es el portaligas?