Alfred Gunning was a cardiothoracic surgeon in Oxford, perhaps best known for his work on replacement heart valves. He was born on 21 November 1918 in Dullstroom, South Africa, the son of George Ronald Gunning, a police sergeant, and Kathleen Gunning née Dunne, a housewife. He attended the Christian Brothers' College, Kimberly, and then the University of Cape Town Medical School, where he was a contemporary of Christiaan Barnard and came under the influence of Charles Saint at Groote Schuur Hospital. He went to England, attended the primary and final fellowship courses, and also the ear, nose and throat course at the Royal College of Surgeons in 1949. Following junior surgical posts he was appointed as a first assistant to Philip Allison in Leeds, an acknowledged expert on oesophageal surgery. In 1964 Allison was appointed Nuffield Professor of Surgery at the Radcliffe Infirmary, Oxford, and Alfred moved with him. He was soon granted consultant status and began to develop the new specialty of open-heart surgery. Alfred spent six months with Kirklin at the Mayo Clinic, and brought back an early type of heart-lung machine to replace the earlier technique of profound hypothermia for the treatment of congenital heart disease in children. In association with a Spanish surgeon, Carlos Duran, he developed a reliable method to preserve human heart valves by a freeze-drying technique. He subsequently introduced the technique to a fellow South African surgeon, Donald Ross, at the National Heart Hospital in London, where the first homograft valve replacement operation was performed in 1962. Because of the difficulty in obtaining human valves, Alfred researched the use of pig valves (identical in size to those of humans) and performed the first aortic valve replacement with a pig valve on a 56-year-old man in 1964. Alfred was later appointed to the Churchill Hospital in Oxford and developed a simple portable heart-lung machine to perform emergency pulmonary embolectomy in peripheral hospitals, an innovation subsequently adopted by Matthias Paneth at the Brompton Hospital, London. In association with Macfarlane and Biggs at the haemophilia unit, Alfred also undertook hazardous open-heart and thoracic surgery on haemophiliac patients. He was a remarkable all-round surgeon, whose operating lists often included abdominal and gynaecological surgery. Problems with funding, and therefore a failure to develop cardiac surgery in Oxford, were a major disappointment to him in the later stages of his career. He was a remarkably unassuming surgeon who nevertheless inspired dedication in those who worked with him. On one occasion he entered the ward late at night and was mistaken by the nurse for the plumber, and was asked to repair a leaking tap. He fixed the tap and then asked the nurse if he could now do his ward round! He was a member of Pete's Club, a travelling surgical club where the only rule was that 'no case that is presented shall throw credit on the presenter'. Only errors of judgement were discussed, and members consequently learnt a tremendous amount, much more than at other national surgical meetings. In 1987, on retirement from the NHS, Alfred returned to Groote Schuur Hospital, Cape Town, where he spent five years as a senior lecturer, doing thoracic surgery. He later became acting head of the department until a full-time professor could be appointed. During his retirement he enjoyed squash and parachuting, and in South Africa bunjee jumping and white water rafting, as well as developing an interest in medical history. He was a remarkable and innovative surgeon who had an international reputation as a lecturer. Sadly, he did not receive in England the acknowledgement and recognition that was due to him, perhaps because of his somewhat unconventional attitude. He married Mary Janet ('Mollie') in 1949. She predeceased him. They had two sons, Kevin, who became director of the John Farman intensive care unit at Addenbrooke's Hospital, and Andrew, and a daughter, Peta. Alfred died on 10 August 2011.