Proval was born in Brooklyn, New York, of Jewish heritage, the son of Clara Katz, an Actress from Bucharest, Romania. He has appeared in such feature films as The Shawshank Redemption, The Phantom, Mob Queen, Four Rooms, UHF, Innocent Blood, The Siege, The Monster Squad, Bookies, Balls of Fury, had cameos in The Brady Bunch Movie and Smokin' Aces, and has had recurring roles in television shows such as Picket Fences, Boomtown and Everybody Loves Raymond. He appeared on Kojak, The Equalizer, Miami Vice, and Friday the 13th: The Series. He appeared in the 14th episode of The West Wing - "Take This Sabbath Day" - as Toby Ziegler's rabbi.