Nelson appeared as Grant Decker in "Threat of Evil", a 1960 episode of "The DuPont Show with June Allyson". His additional television credits include guest appearances on "Alfred Hitchcock Presents", "Ben Casey", "The Twilight Zone" (episode "Stopover in a Quiet Town"), "Dr. Kildare", and in later years playing a hobo on an episode of "The Ropers". He appeared regularly on television in the 1960s, having been one of the "What's My Line?" mystery guests and later serving as a guest panelist on that popular CBS quiz show. Nelson was also a semi-regular panelist on the daytime and nighttime versions of "To Tell the Truth" for three years of its run from 1962-65, as well as a guest panelist a few times in 1967. Nelson appeared second most frequently on the daytime show in the three years he was a semi-regular. he hosted portions of the NBC Radio program "Monitor". Nelson appeared in both the stage and screen versions of "Mary, Mary".