Beginning his career in the film industry, Denisof was the fight director for a stage production of "Hamlet", and in 1991 was the fight director for the BBC's "The Other Side", "Romeo and Juliet", and "The Soul's Dark Night". His first lead role was alongside Christopher Lee in the feature film "Murder Story" (1989) where he played an investigative reporter. One of his first known works in television was on the arcade version of the video for "Got My Mind Set On You" by George Harrison. In 1995 he landed a small part in the 1995 movie "First Knight", appearing as one of Arthur's round table knights in multiple scenes with Sean Connery and Richard Gere. Following those roles, Denisof worked with Sean Bean in three episodes of "Sharpe" as Lord John Rossendale in 1997.