Oswald Tubbs was born on 21 March 1908 in Hadley Wood, Middlesex, the son of Sydney Walton Tubbs, a chartered accountant, and his wife Mabel, née Frost, a butcher's daughter. He was educated at Shrewsbury and at Gonville and Caius College, Cambridge, where he was an enthusiastic oarsman. Unhappily he was then afflicted by pulmonary tuberculosis and, there being at the time no effective chemotherapy, he was treated surgically by Russell Brock, who excised the affected lobe. The treatment was very successful and the experience determined the direction of his subsequent career. He then went to St Bartholomew's for his clinical studies and qualified there in 1932. He held junior surgical posts at his teaching hospital and at the Brompton before going to the Lahey Clinic, Boston, with a Dorothy Temple Cross Fellowship for research in tuberculosis. He was appointed to the consultant staff of both St Bartholomew's and the Brompton Hospital and in 1941 made history by ligating a patent ductus arteriosus in a patient suffering from bacterial endocarditis: the operation with sulphapyridine cover proved effective. He served in the Emergency Medical Service throughout the war and became one of the leaders of the post-war expansion of the field of cardiothoracic surgery. He advanced the surgical treatment of valvular disease but retirement came too soon to enable him to play a part in the development of coronary artery grafting. He was President of the Society of Thoracic and Cardiovascular Surgeons in 1971 and of the Thoracic Society in 1974. He married in 1934 Marjorie Betty Wilkins, by whom he had two children: Jill, who became a physiotherapist, and Oswald Nigel Tubbs, FRCS, an orthopaedic surgeon in Birmingham. He died on 12 November 1993 after a retirement spent happily in the garden or by the river bank. His wife Betty, whose bubbly personality was an excellent foil for his own, had predeceased him.