In an interview with journalist Robert K. Elder for The Film That Changed My Life, Hiller states that the film Rome, Open City (1945) had had a strong influence on his career because he saw it right after leaving the military where he was a bomber navigator in the Canadian Air Force. The film is set during the Nazi occupation of Italy and shows the priesthood and the Communists teaming up against the enemy forces. Hiller commented, "You just get the strongest emotional feelings about what happened to people in Italy."
Hiller preferred his scripts to contain "good moral values," a preference which he says came from his upbringing. He wanted high quality screenplays whenever possible, which partly explains why he collaborated on multiple films with both Paddy Chayefsky and Neil Simon. Hiller explains his rationale: