Kenneth Till was a paediatric neurosurgeon at Great Ormond Street Hospital, London. He was born in Stoke-on-Trent on 12 February 1920, the son of Reginald Till, a ceramic designer, and his wife, Grace Adelaide née Smallcombe. He was educated at Poole Grammar School, Dorset, and later at Downing College, Cambridge, and St George's Hospital Medical School, London, winning an Anne Selina Fernee scholarship and the Brackenbury surgical prize. He graduated in 1944 and, while a house surgeon at St George's, encountered neurosurgery in the form of Wylie McKissock, into whose operating theatre he ventured at Atkinson Morley's Hospital, Wimbledon, a branch of St George's. McKissock was impressed and offered him an appointment as a neurosurgical house surgeon at Great Ormond Street Hospital where, ultimately, he made his career. After house jobs at St George's and National Service in the RAF, he obtained the FRCS in 1953 and was appointed first assistant to McKissock at Great Ormond Street. He spent 1956 at the Chicago Memorial Children's Hospital, and in 1959 he was appointed as a consultant neurosurgeon at Great Ormond Street, where he remained single-handed until 1970. He also held a consultant appointment at University College Hospital and honorary appointments at the Whittington Hospital, London, and Queen Mary Hospital, Carshalton, Surrey. Till was an exceptionally rapid surgeon, with wide interests. Together with the engineer, Stanley Wade, and the author Roald Dahl, whose son had developed hydrocephalus following a head injury and was under Till's care, he helped develop the Wade-Till-Dahl valve for the treatment of this condition. This device, which followed the appearance of the first valved shunts in the US designed by Holter and Nulsen, was simple, cheap, re-sterilisable and less likely to become blocked with debris, since the valves were of metal. It had considerable success, though it did not provide a pressure against which the CSF drained, a consideration that subsequently became regarded as important and led to more complex designs. Till's contributions to the literature covered a number of topics, especially craniopharyngioma and spinal dysraphism. He was involved in the development of Great Ormond Street Hospital as a centre for cranio-facial surgery and was a founding member of the International Society for Pediatric Neurosurgery. In 1975, he published a textbook, *Paediatric neurosurgery: for paediatricians and neurosurgeons* (Oxford, Blackwell Scientific). After retirement he moved to Somerset and acted as a technical adviser to publications which included the *British Journal of Neurosurgery* and the *Journal of Neurology, Neurosurgery and Psychiatry*. He married Morwenna Tunstall-Behrens, a doctor who had engaged in leukaemia research and was also a distinguished plantswoman. They had one daughter and three sons. Till's interests outside the profession were gardening, photography and music. He died on 8 July 2008 of complications of Waldenström's macroglobulinaemia.