Actor Adam Rich was missing from the televised reunion, part of the "Great TV Families Reunited" series on NBC's "Today Show."
"Eight is Enough" followed the story of a journalist, played by Dick Van Patten, and his eight children, played by Grant Goodeve, Lani O'Grady, Laurie Walters, Susan Richardson, Dianne Kay, Connie Newton, Willie Aames, and Adam Rich.
Diana Hyland played Van Patten's wife in the first few episodes but dropped out when she was diagnosed with breast cancer. Betty Buckley, who later came on the show as a love interest, became the second wife.
Watch the Reunion
The show ran for five seasons, from 1977-1981.
Rich's adult life has been plagued by substance abuse and legal troubles. In 1991, he was arrested for trying to break into a pharmacy to steal narcotics. Van Patten, who played his father on "Eight is Enough," bailed him out. Most recently, he was arrested in 2003 for driving while intoxicated, when he reportedly came close to hitting a police car in Los Angeles.