He made his stage debut in Night Must Fall in Coral Gables, Florida, and then appeared in Tea and Sympathy in the role of Tom Lee at the Coconut Grove Playhouse in Miami, and in The Lady's Not for Burning, Death of a Salesman, Thieves' Ball, and A View from the Bridge at the Highland Park Playhouse in Chicago.

According to Thomas W. Ennis writing in The New York Times, Tennessee Williams saw Drivas in Tea and Sympathy and asked him to take the lead in his play Sweet Bird of Youth,[1] which had its premiere in Coconut Grove at George Keathley's Studio M Playhouse in 1956.

[2] He made his Broadway debut in the role of Ramses in 1958 in the play The Firstborn, directed by and starring Anthony Quayle as Moses.

[3] He continued to perform on stage, as Jacko in the Beverley Cross play One More River (1960), with George C. Scott in the Warsaw Ghetto play The Wall (1960), as Alfred Drake's son Giorgio in the Italian Renaissance set Lorenzo (1963), as the British beatnik son of Cyril Ritchard in The Irregular Verb to Love (1963), and in And Things That Go Bump in the Night (1965), which he also directed.

Other directing credits include Bad Habits, for which he won an Obie Award, Legend, Cheaters, It Had to Be You, the 1982 revival of the musical Little Me (with his work there praised by theater critic Clive Barnes who wrote "The whole balance is set right by the present production's firmer sense of form and continuity.