He was born on 14 December 1900 son of D C Lysaght of Portskewett House, St Pierre, Chepstow, Monmouthshire; his family had large steel interests in Britain and the Commonwealth. On leaving school he joined the Navy but was invalided out after two years. He then started pre-clinical studies at Bristol, where his great-grand-father had been Lord Mayor, trained at Guy's Hospital, and qualified in 1925. He returned to Bristol as house physician at the Royal Infirmary and, after further resident posts at Leicester and Newcastle-upon-Tyne, the Royal Cancer Hospital and St Peter's Hospital for Stone, he was appointed to the staff of the Royal Infirmary, Cardiff in 1934 and became a clinical teacher at the Welsh National School of Medicine. On the outbreak of war in 1939 he joined the RAFVR as a surgical specialist, serving at home and in Iceland. He was particularly interested in the surgery of the rectum and colon, but did not publish his results considering this a form of self-advertisement; he rarely attended medical meetings, except for the Moynihan Chirurgical Club. He was a big man standing six-foot-four and broad in proportion, a great advantage in the crowd at Cardiff Arms Park where he watched every Rugby match that he could; he loved cricket too, possessed and studied a complete set of Wisden, and was an active supporter of the Glamorgan county eleven; he also kept a yacht at Fowey. He bought vintage cars, suddenly exchanging an early Bentley for a Renault mini, and the sight of such a large man emerging from such a small car caused amusement. These foibles endeared him to his students and colleagues. Lysaght was generous, friendly, big-hearted and honest in all things. It was a source of admiration that so clumsy-looking a man could be so skilful a surgeon. He married in 1939 Jacqueline Heard, who survived him with their two sons and two daughters. He lived at Steynton, Lisvane, Cardiff and died in the Royal Infirmary on 11 November 1964 aged 63.