Peppard made his first television appearance, with a young Paul Newman, in an episode of The United States Steel Hour in 1956. A Broadway appearance in "The Pleasure of His Company" in 1958 led to a MGM contract. His good looks and elegant manner helped him receive his most famous film role as Paul Varjak in Breakfast at Tiffany's (1961) with Audrey Hepburn. This role made him a major film star lasting from the early to late 60's. However, choose tough guys roles in big, ambitious pictures where he was somewhat overshadowed by ensemble casts. A drinking problem also started to effect his reputation.

After a string of B films in the early 70's Peppard moved to television. He had a leading role in the TV series Banacek (1972 - 1974), (part of the NBC Mystery Movie series of the 1970s), and played in Doctors' Hospital, in 1975, and in several other television films, which became in the later part of his career his major dedication.

He was married five times, and the father of three children:

1) Helen Davies (1954-1964) (two children) 2) Elizabeth Ashley (1966-1972), his co-star in The Carpetbaggers (One son Christian) 3) Sherrry Boucher (1975-1979) 4) Alexis Adams (1984-1986) 5) Laura Taylor (1992-1994) Peppard finally gave up drinking in 1978 and spent his later years trying to help other alcholics enter into recovery.

A life long smoker Peppard was diagnosed with lung cancer in 1992. He died of pneumonia on May 8, 1994, at the age of 65. He is buried in Northview Cemetery in Dearborn, Michigan.