Klugman died at his home in Northridge, California. He was diagnosed with throat
cancer in 1974 and lost a vocal cord to cancer in 1989, but continued to act. The
exact cause of his death is not known.
He was best known as Felix Unger‘s sloppy roommate Oscar Madison in the ABC
television series The Odd Couple (1970–1975), for his starring role in Quincy, M.E.
on NBC-TV (1976–1983), as Juror #5 in 12 Angry Men, and multiple appearances
on The Twilight Zone.