Leslie Herbert Worthy Williams was born at Newport, Monmouthshire on 27 February 1893, the son of the late Mr T Gill Williams and Mrs Williams (née Willey). He was educated at Newport Intermediate School, University College, Cardiff and University College Hospital, London, where he qualified with the Diploma of the Conjoint Board in 1914. He served with the RAMC until 1920 when he returned to University College Hospital and graduated MB BS. He became a Fellow of the Royal College of Surgeons in 1921 and proceeded to MD and MS in the following year. He held junior appointments at University College Hospital and was then appointed in turn to the posts of obstetric registrar, radium registrar, registrar in venereal diseases and chief assistant to the Professorial Unit in obstetrics in the same hospital. In 1930 he was appointed obstetric and gynaecological registrar at St Mary's Hospital and in 1931 he joined the honorary staff of that hospital as second obstetric surgeon to outpatients. He was appointed consultant surgeon to the Samaritan Hospital and consulting obstetric surgeon to the Nelson Hospital, Wimbledon. He was also a consulting surgeon to the London County Council and medical inspector in nullity to the High Court. He acted as examiner to London University, Cambridge University and to the Conjoint Board. He was a foundation member of the Royal College of Obstetricians and Gynaecologists, became a Fellow in 1934 and served on its Council from 1949 to 1952. In 1949 he visited Sydney as the first William Mcllrath Guest Professor to the University of Sydney and in 1962 he gave the James Young Simpson Oration. He wrote *Aids to obstetrics* (13th edition 1956) and, with Alex Bourne, several editions of *Recent advances in obstetrics and gynaecology*. He was an excellent teacher who emphasised principles and made his subject logical. His emphasis on essentials was such that their practical application was straightforward. He was a cheerful, happy person who enjoyed meeting people and who delighted in his golf, at which he was an outstanding performer. He was appointed Captain of the Royal Wimbledon Golf Club and he was a popular member of the Savage Club. He supported many student activities at St Mary's Hospital Medical School and he was President of the Golf Club. An ideal "Chief", he was always loyal to his subordinates. He gave his opinion on all matters without fear or favour, but if this opinion was not taken he submitted gracefully to the views of the majority. He opposed the entry of women students to St Mary's Hospital Medical School after the second world war, but when they were admitted he accepted the situation without acrimony. He opposed strongly the formation of a Professional Unit in obstetrics at St Mary's Hospital because he felt that the academic approach would destroy the practical application of the subject. He had retired before this project was finally introduced. He died on 1 January 1972, and was survived by his wife, Patrice, elder daughter of the late Hattor Ronayre Connor of Douglas, Co Cork, a daughter and two sons, the elder of whom was educated at St Mary's Hospital Medical School and is an ophthalmic surgeon in the Royal Navy.