John Parker was a consultant cardiac surgeon at St George's Hospital, London. He was born in Harrow on 1 February 1938, where his father, Kenneth Kershaw Parker, was a civil servant and a town planner. His mother was Mary Moore. He was brought up in Salisbury, Rhodesia (now Harare, Zimbabwe), where he attended the David Livingstone School and the Churchill School. He was school captain and captain of rugby, and won a scholarship to St Andrews University. Entering St Andrews in 1956, he won innumerable prizes, and made a name for himself as a formidable debater, becoming president of the Scottish Union of Students from 1961 to 1962. He qualified in 1962 and did his house jobs on the surgical and medical professorial units, staying on as a lecturer in the department of surgery in the University of St Andrews under Sir Donald Douglas and gaining his MRCP in 1966 and FRCS Edinburgh and England in 1967. His rejoining the professorial unit in Dundee in 1967 determined his future career in cardiothoracic surgery and he came to London, to the Brompton Hospital, in 1968. In 1969 he was appointed senior registrar in the London training programme, which included rotation to the National Heart Hospital, and in 1970 he spent a year with John Kirklin in Birmingham, Alabama, as a surgical fellow. His research while there, into lung water, led to an Hunterian Professorship in 1972, the year that he returned to the National Heart Hospital as locum consultant and senior lecturer, a post he held for four years. He was appointed consultant cardiac surgeon to St George's Hospital in 1975 where he re-activated, single-handedly, the cardiac surgical programme, collaborating with Aubrey Leatham, and operating every day, at first with little support. His personal effort and excellent results led to successful expansion of the unit before and after the move to Tooting, and his organisational skills included the successful acquisition and administration of his own departmental budget. He obtained funding from the British Heart Foundation for university chairs in cardiology and cardiovascular pathology at St George's, and from the Government's private finance initiative to build a successful centre for cardiology neurology and surgery at St George's. He was elected President of the British Cardiac Society, the first surgeon to hold this position, and during his tenure of office he organised the purchase of their building in Fitzroy Square and a revision of their constitution, which enabled it to widen its membership to include nurses and other health service professionals. He was President of the cardiothoracic section of the Royal Society of Medicine from 1993 to 1995, and vice-president of the Society of Cardiothoracic Surgeons of Great Britain and Ireland, and was due to become President in the month of his death. At national level, he was concerned with the RITA trials that compared angioplasty with surgical and medical treatment of coronary disease, the Read Centre on coding and terms for cardiology and cardiothoracic surgery, and the Clinical Standards Advisory Group. He received the Clement Price Thomas award in 1992. Internationally, he was Chairman of the working group on cardiovascular surgery for the European Society of Cardiology. His hobbies included sailing and farming, and he was an honorary consultant in surgery to the Royal National Lifeboat Institution from 1984. He married Veronica (Niki) Good in 1963 and had two sons, Andrew and Simon, and a daughter, Jackie. He died on 23 March 1998 of a brain tumour.