E. Barnard ("Barney") Fuller was a son of Sir Thomas E. Fuller, Cape parliamentarian and journalist, and younger brother of Dr Arthur Fuller*. Barnard studied at Dale College in King William's Town and then at the South African College, Cape Town, from 1883 to 1887. He won the college's gold medal, passed the matriculation examination of the University of the Cape of Good Hope in 1885, and the intermediate examination in arts (equivalent to the first year of the BA degree) the next year. Around this time he collected some plants in the vicinity of Cape Town, which were presented to the Edinburgh Herbarium. Proceeding to Scotland in 1887 to study medicine he qualified as Bachelor of Medicine (MB) and Master of Surgery (CM) with first class honours at the University of Edinburgh in 1891, with the help of two scholarships. He became a licentiate of the Royal College of Surgeons of Edinburgh the same year, and a Fellow two years later. After working for a year as house surgeon and house physician at the Royal Infirmary in Edinburgh he returned to Cape town, where he remained for the rest of his life. He was licensed to practise in the Cape Colony on 30 December 1892 and early in 1893 commenced to do so.
Fuller was a very distinguished figure in the history of South African medicine and made pioneering contributions to the development of public health, medical education and surgery. In 1893 he was mainly responsible for organising the Second South African Medical Congress, which was held in Cape Town towards the end of that year. Four decades later he was President of the 27th Congress, held in 1933. Early in 1894 he became consulting medical officer to the city council of Cape Town. Soon he was appointed as the first permanent medical officer of health of the city and retained that position to 1902. As early as 1893 he contributed a paper on "Public Health in the Colony" to the South African Medical Journal, and from April 1896 began to serve as editor of the journal's new public health section. In 1896 he was furthermore elected a Fellow of the Incorporated Society of Medical Officers of Health of Great Britain.
Fuller's published contributions to surgery and medicine started in 1894 with a paper on occlusion of the rectum in The Lancet. A paper on the diagnosis and treatment of diphtheria appeared in the South African Medical Journal the next year. For 22 years, from 1904 onward, he contributed numerous papers on a variety of topics in surgery and medicine to the South African Medical Record (1903-1926), plus a paper on "The treatment of forms of puerperal fever" in the Transvaal Medical Journal (1907/8, Vol. 3). In 1916 to 1918, during World War I (1914-1918), he was in command of the Surgical Division at No. 2 General Hospital, Maitland, with the rank of Lieutenant-Colonel. For 35 years from about 1898 he was visiting surgeon to New Somerset Hospital. During the 1920s he initiated the surgical speciality of urology there, and became a member of the International Urological Association. He also wrote a textbook on urology. In 1922 he visited the United States and after his return attempted to obtain some of the newly discovered drug insulin from its Canadian discoverers, but the drug was still too scarce and unstable to send to South Africa.
Fuller's role in medical education commenced in 1895, when he gave "Ambulance lectures" at the South African College, mainly for mining students. In 1903 he began to promote the idea of a medical school for Cape Town, among others in an article on "The need of a medical school for South Africa" in the South African Medical Record (1904). That year, while on a visit to England, he negotiated with medical schools there for the registration of medical students upon their entry at the South African College and holding of the first year medical examinations in Cape town. He was chairman of senate of the South African College from 1908 to 1917 (when it became the University of Cape Town) and made special efforts to have Chairs of anatomy and physiology created and a suitable building for these subjects erected, which was accomplished in 1911. In 1917 he published The beginning of medical education in South Africa, containing reprints of four of his speeches on the topic. Thus he was for years the most important driving force behind the eventual establishment of a medical school at the University of Cape Town. He lectured there in clinical surgery, and served as an examiner.
From 1902 Fuller served on the council of the South African College, and in 1918 continued as a member of council of its successor, the University of Cape Town, serving as chairman from 1938 to 1945. In recognition of his services the university awarded him an honorary Doctor of Laws degree in 1940.
Fuller served on the Colonial Medical Council and its successor, the South African Medical Council. He was a member of the Cape Town City Council for six years from 1901. In 1895 he joined the South African Philosophical Society and was elected on its council for 1896/7. He was still a member when it became the Royal Society of South Africa in 1908. He also joined the South African Association for the Advancement of Science soon after its formation for a few years. In 1907 he was president of the Cape of Good Hope Branch of the British Medical Association, of which he had been a member since at least 1895. By 1898 he had also joined the new South African Medical Association.
Fuller, like his older brother, was a keen sportsman. He founded the University Tennis Club in Edinburgh in 1891 and won a doubles tennis championship there; later he became singles champion of the Western Province. Continuing to take an interest in sport, he served as chairman of various sports bodies. In 1893 he married Maria Emmeline Buchanan. In his later years he was much troubled by arthritis.