Gunter was educated at Melbourne University, qualifying MB BS there in 1945 and gaining his MS in 1950. He held junior appointments at the Royal Melbourne Hospital from 1945 to 1949. He came to Britain in 1950 and passed the FRCS examination in that year. After spending a year at Frenchay Hospital, Bristol, he returned to Australia and settled in Melbourne, where he opened a practice. He was a staff specialist at Prince Henry's Hospital, (1952-1968), staff specialist at the Royal Children's Hospital (1968-1980), and consultant at the Royal Women's Hospital (1980-1985). He died on 29 July 1994.