Betty Underhill was born on 22 December 1908, the only child of William Wood and Elizabeth Roberts, both head teachers. She was educated at North London Collegiate School and Somerville College, Oxford, where she gained a first class honours degree in zoology. She remained at Oxford doing research in genetics and cytology for her BSc and then obtained the London diploma in education and the Board of Education teaching certificate. From 1932 to 1943 she followed the family tradition and taught biology, first at King's Norton Secondary School for Girls and then at the County School for Girls, Ealing. In 1943 she entered the London School of Medicine at the Royal Free Hospital where she won prizes in anatomy, paediatrics and public health. She qualified with the Conjoint Diploma in 1947 gaining the MB, BS the following year. After junior appointments at the Royal Free Hospital, Leicester Royal Infirmary, and at Chase Farm, Whipps Cross and Central Middlesex Hospitals she gained her FRCS in 1953. She completed her training at Frenchay Hospital and the Royal Marsden. In 1956 she went abroad under the aegis of the Ministry for Overseas Development and held various posts in Bahrain and the West Indies. For a period she was appointed lecturer in surgery at the Barbados campus of the University of the West Indies. She returned to England in 1973 to live in West Sussex but continued to act as locum surgeon at Worthing and Chichester for several years. Miss Underhill was a keen supporter of the Medical Women's Federation and was President of the Sussex Association in 1977-78. She was also an active Fellow of the Royal Society of Medicine. Her main hobbies were gardening and photography and she exhibited at many major international photographic exhibitions. She was also very fond of travel and cookery and mentioned on her curriculum vitae that she had been twice round the world, once via the northern and once via the southern hemisphere. She never married and died peacefully at home on 14 May 1983.