Sterling Bunnell was born in San Francisco on June 17, 1882, the son of James Sterling Bunnell and Catherine Mapes Bunnell. He received his B. S. from the University of California in 1904 and his M. D. from the University of California Medical School in 1908. He interned at St. Luke's Hospital from 1908 to 1909. Early in his medical career he became deeply interested in experimental work in tendon and nerve sutures and grafts, and in the surgical problems of the extremities. This was the beginning of a lifetime work devoted to the restoration of the crippled human hand.