Guillaume Tom du Toit, known as 'Gumee', was professor of orthopaedic surgery at the University of Pretoria, South Africa. He was born in Johannesburg on 22 November 1909, the son of Guillaume Johannes Izak du Toit, headmaster of the Abraham Kriel Orphanage at Langlaaglte, which had been founded for orphans from the Boer War. His mother was Esther Van der Merwe, like his father, from an old Huguenot family. He was educated at Helpmekaar High School and Witwatersrand University, where he won honours in all the preclinical subjects. He continued his clinical studies at St Bartholomew's Hospital in London, where he graduated in 1932. He quickly passed the FRCS and returned to Johannesburg as an honorary clinical assistant in the department of surgery at Johannesburg Hospital. At first a general surgeon, he developed a keen interest in orthopaedics and in 1938 won a Nuffield grant to study orthopaedics under G R Girdlestone in Oxford. This was one of the first awards by the Nuffield Trust Fund set up by Lord Nuffield in 1937 to develop orthopaedic surgery in South Africa. Later du Toit was to be a trustee and member of its executive committee. He was elected as an honorary secretary of the Orthopaedic Surgeons' Group of South Africa in 1942, which later became the South African Orthopaedic Association. He was professor of orthopaedic surgery at the University of Pretoria from 1965 to 1971, and subsequently an honorary professor at the University of Witwatersrand. A sharp-witted, charismatic man, he influenced a generation of orthopaedic surgeons in South Africa. He set up the Workers' Rehabilitation Hospital in Johannesburg, and a spinal cord injury centre in Pretoria, and even after retirement continued to carry out research into cartilage and free muscle grafting, the aetiology of Mseleni joint disease, and the mathematical enigma of correcting a three-dimensional bone deformity with a single osteotomy. He was frequently invited to the USA as a guest speaker and was an honorary member of the American Academy of Orthopaedics. He died on 6 April 1999, leaving a widow, Johanna ('Joey') van Wyk and three daughters (Susan, Estelle and Delphine) and one son (Guillaume).