At the encouragement of his parents, Rubinek began taking acting lessons and joined the Ottawa Little Theatre. In 1969, he began performing at the Stratford Festival. He made lasting contributions to the Toronto theatre scene, co-founding the Canadian Stage Company and working extensively with Theatre Passe Muraille as an actor and producer. He began working in the United States in the 1970s, acting in Off-Broadway productions. In 1984, he won a Drama-Logue Award for Des McAnuff's La Jolla production of "As You Like It".