Prine was born in Jennings, Florida. After graduation from Miami Jackson High School in Miami, Prine made his acting debut three years later in an episode of United States Steel Hour. His next role was in the 1959 Broadway production of Thomas Wolfe’s Look Homeward, Angel. In 1962, Prine was cast in Academy Award-nominated film The Miracle Worker as Helen Keller’s older brother James.

In 1962, Prine landed a lead role with Earl Holliman in the 28-episode series Wide Country, a drama about two brothers who are rodeo performers. After Wide Country, Prine continued to work throughout the 1960s and 1970s, and in such television series as Gunsmoke, Bonanza, The Virginian, Wagon Train, Dr. Kildare, Baretta, Hawaii Five-O, Twelve O’Clock High, and The Bionic Woman. He played Dr. Richard Kimble’s brother Ray in an important first-season episode of The Fugitive.