The son of concert violinist Efrem Zimbalist and famed opera singer Alma Gluck, Zimbalist turned to acting after military service during World War II. He trained at the Neighborhood Playhouse (alongside Gregory Peck) and made his stage debut in 1945 in New York with "The Rugged Path" before joining Eva LeGallienne's American Repertory Theatre Company for several years. He also produced plays, including "The Consul" (1950).
Zimbalist made his screen debut as Edward G. Robinson's clothes-hoarding son in "House of Strangers" (1950). That same year, his first wife died and he left acting for two years to work as a music researcher for his father and raise his two children. When he resumed his acting career, it was in feature films like the war story "Bombers B-52" and "Band of Angels" (both 1957), in which he was the Union soldier who aids a woman of part African descent (Yvonne De Carlo). As Zimbalist turned to TV, his feature appearances became infrequent, but he won praise as Audrey Hepburn's husband in "Wait Until Dark" (1967) and played the injured pilot in "Airport 1975" (1974). More recently, Zimbalist did a small role in "Hot Shots" (1991) and played a man escaping from prison and seeking revenge in "The Avenging" (1992).
Television took over the bulk of Zimbalist's career starting in 1957 when he did an episode of the anthology series "Conflict". In the show, he played Stuart Bailey, an erudite private investigator. The character was given his own ABC series in 1958, "77 Sunset Strip", in which Zimbalist and Edd 'Kookie' Byrnes operated out of a West Hollywood restaurant/office. Simultaneously, he had a recurring role as Dandy Jim Buckley on "Maverick ABC, 1957-1960). When "77 Sunset Strip" ended, ABC cast the actor as the dour Inspector Lewis Erskine in "The F.B.I." Each week, he caught his man, always upholding the sanctity of the Bureau and its (unseen) leader, J. Edgar Hoover. In the 80s, Zimbalist occasionally appeared on "Remington Steele", the NBC private investigative series starring his daughter, Stephanie Zimbalist, playing her mentor. In 1990, he briefly played Don Alejandro de la Vega, the swashbuckler's father on "Zorro: The Legend Begins" (The Family Channel). By the 90s, Zimbalist was seen infrequently in front of the cameras, but his voice could be heard on numerous animated series, including "The Legend of Prince Valiant" (The Family Channel, 1991-95), as King Arthur.