Thomson was born on 14 July 1919 in Brisbane, the son of Frederick Thorpe Thomson, an insurance executive, and his wife Ann Margaret, née Evans. He was educated at Brisbane Boys' College, before winning an open scholarship to the University of Queensland where he won the W N Robertson medal for first place in the final examination, the E R Russell memorial prize for first place in clinical medicine and the University gold medal for outstanding merit. Shortly after qualification in 1942 he joined the medical branch of the Royal Australian Air force and served until November 1945 in a part-time capacity in conjunction with posts at Brisbane General Hospital, where he was surgical registrar from 1946 to 1948. Coming to London in 1949, he worked at Guy's Hospital and the Royal Cancer Hospital among other hospitals. After obtaining his Fellowship he returned to Brisbane and was engaged in private surgical practice there until he retired at the end of June 1991. In addition to his private practice he was senior surgeon to the Princess Alexandra Hospital 1956-71 and honorary consultant surgeon thereafter. He was a skillful surgeon with an interest in thyroid and bowel work. He was clinical lecturer in general surgery to the department of surgery, University of Queensland 1951-71 and examiner in surgery for that period, and investigated and reported to the university on the problems of administration of clinical teaching. He served on numerous committees of the Royal Australasian College of Surgeons and of the Australian Medical Association, and was President of the Queensland branch 1967-8 and a life Vice-President thereafter. He was President of the 4th Australian Medical Congress and Chairman of its organising committee 1971 and Vice President of the 5th Australian Medical Congress 1974. He was President of Council of the Australian Medical Association 1970-72. He was a frequent guest lecturer at universities overseas, particularly on the Queensland melanoma project, on which he spoke at King's College Hospital, London, the Royal Infirmary at Edinburgh, and the University Hospital, Edmonton, Alberta. He was honorary surgeon to H M the Queen, to H R H the Duke of Edinburgh and H R H the Princess Anne, to T R H the Duke and Duchess of Gloucester and to T M the King and Queen of Thailand. Evan Thompson was a committed Christian, a member of the Christian Medical Fellowship and of Gideons International. He was also a lay preacher. His recreations were golf and reading philosophy, theology, ethics and law. He married Mary Kennedy, a trained nurse, on 18 June 1955. His wife was also a leader in community affairs, for which she was awarded an OBE. There were no children of the marriage. Sir Evan, whose health, latterly, had not been good, was killed in a motor car accident on 14 January 1993. He was survived by his wife.