During the early days of talkies he served as a translator and vocal coach for French language versions of American-made films.

Two of his notable credits include the classic 1942 film Casablanca in a small role as an announcer for a French radio station in one of the opening scenes, and historical figure Ferdinand Foch in the 1941 film Sergeant York, based on the life of Alvin York.

His most well-known role was comatose scientist Dr. Jan Benes in the 1966 science fiction film Fantastic Voyage.

: first, uncredited in the episode "A Day in June", followed by "No Trumpets, No Drums" as Marceau, then as a French farmer in "Birthday Cake", Father Bomar in "The Steeple", and Brother Edmundo in "The Mockingbird".

Del Val died at age 83 from a heart attack in Pacific Palisades, California.