Born in New York City, Prager spent three years at Johns Hopkins University before working in summer stock and on Broadway, where he appeared in The Skin of Our Teeth and The Eve of St.

He told an interviewer in 1969 that as an actor he appeared in “all the parts that Phil Silvers wouldn't play.”[1] Prager returned to Broadway and won critical praise in 1951 for his performance in the Comden and Green revue, Two on the Aisle.

[2] In March 1953, former screenwriter Bart Lytton, told the House Un-American Activities Committee that Prager was among the persons he had seen at Communist Party meetings.

Additional theatre directing credits include Bravo Giovanni, Minnie's Boys, Don't Drink the Water, and 70, Girls, 70.

Prager's television directing credits include The Love Song of Barney Kempinski for ABC Stage 67, Car 54, Where Are You?, and The Patty Duke Show.