Aubrey York Mason, one of the many South Africans to distinguish themselves in British medicine, came late to the Royal College of Surgeons but gave loyal service to it in a succession of roles throughout his consultant career. He was born in Pietermaritzburg, Natal, South Africa, on 9 February 1910, the son of a farmer, Albert Augustus, and Jessie Leonora, née Peckham. He showed early promise at the Ladysmith High School and went on to Witwatersrand University in Johannesburg. He qualified there with the MB BCh in 1935, taking the medal for the most distinguished medical graduate. After a series of junior hospital posts in the Johannesburg General Hospital he became lecturer in surgery to the University. He did a spell in the Mayo Clinic but came to Britain in 1939 to take the Edinburgh Fellowship. He enlisted in the RAMC and served in India as major, surgical specialist. After the war he was determined to stay in England and took both the Membership and the Fellowship of the College in 1949. He was soon appointed as consultant general surgeon at St Helier Hospital, Carshalton, and his career there brought great distinction to the hospital, where a ward was later named after him. His main interest was bowel cancer, on which he wrote extensively and which was the subject of his Hunterian Lecture in 1974. His work on cancer was recognized by an honorary appointment at the Royal Marsden Hospital. In the College he was successively Surgical Tutor, Regional Adviser for the SW Metropolitan Region and a member of the Court of Examiners. In 1940 he married Margaret Neil Smith, an anaesthetist from Australia, and by her he had twin sons, Michael, and David, FRCPath, a haematologist. He died on 17 February 1993.