Mineo was bisexual. In 1976 he played the role of a bisexual burglar in a series of stage performances of the comedy, "P.S. Your Cat Is Dead". The play moved from San Francisco to Los Angeles and Mineo moved along with the play. He was arriving home after a rehearsal on February 12, 1976, when he was stabbed to death by a mugger in the alley behind his apartment building. This happened near Sunset Strip in West Hollywood, California. He was buried in Hawthorne, New York.