He was best known for his role as diner owner Mel Sharples on the television sitcom Alice (1976–1985), as well as his multiple guest appearances on The Love Boat (1977–1987).

A lifetime member of the Actors Studio,[4] he was a familiar face on television in the 1960s and 1970s, appearing on numerous series, including The Man from U.N.C.L.E., Star Trek, Bonanza, Here Come the Brides, That Girl, Gunsmoke, The Mary Tyler Moore Show, The Partridge Family, All in the Family, Fantasy Island, Columbo, and The Love Boat.

He also appeared in many films such as Bullitt (1968), Papillon (1973), The Gambler (1974), The Cheap Detective (1978), and All Dogs Go to Heaven (1989), as well as more than 25 stage productions, including Twelve Angry Men, The Diary of Anne Frank, Death of a Salesman, and Brighton Beach Memoirs.

In 1971, he made a guest appearance as Dirks in season 16, episode 19 of the long-running CBS Western series Gunsmoke.

Alice: Life Behind the Counter in Mel's Greasy Spoon (A Guide to the Feature Film, the TV Series, and More).