After studying film at UCLA, Hellman became an assistant to producer/director Roger Corman. He debuted as a director with the 1959 low-budget horror tale The Beast from the Haunted Cave, produced by Corman's brother Gene. In the early '60s he shot footage for Roger Corman's Creature from the Haunted Sea and The Terror, starring Jack Nicholson. Hellman and Nicholson went on to make Back Door to Hell, Flight to Fury, and the memorable westerns Ride in the Whirlwind and The Shooting. In the '70s Hellman directed a trio of offbeat and impressive films starring Warren Oates: the road tale Two-Lane Blacktop, the controversial Cockfighter, and the western China 9 Liberty 37 (aka Clayton and Catherine). His recent work has been more sporadic, but includes the dark swashbuckler Iguana and the slasher film Silent Night Deadly Night III: Better Watch Out.