He was the obscure cab driver in the famous "I coulda been a contender..." scene with Marlon Brando and Rod Steiger in the classic movie On the Waterfront (1954).
In his early years he posed for painters who worked out of studios in Manhattan's Union Square.
Once asked why he chose acting as a profession, he stated that the rise of anti-Semitism in Europe compelled him to prove himself worthy of his "gift of life."
When the Actors Studio was formed in 1947 Persoff was in the first "beginner's" class directed by Elia Kazan. Among his fellow students were Julie Harris, Steven Hill, Cloris Leachman, 'James Whitmore' (QV), Martin Balsam, Kim Hunter and Jocelyn Brando (Marlon Brando's sister.).