Franz was also a familiar face on American television series; he made five guest appearances on "Perry Mason", twice playing the defendant and one time the murderer. In 1958 he played the title role of Danny Harrison in "The Case of the Married Moonlighter," and in 1959 he played Richard Vanaman in "The Case of the Golden Fraud." In 1959, he co-starred in the short-lived series World of Giants. In 1962, he played murderer Mr. Evans in "The Case of the Captain's Coin."