This thesis investigates the development of medical research at the Otago Medical School in Dunedin, New Zealand under Sir Charles Hercus, Dean from 1937-1958. It also explores his interest and participation in research from his student days and the years before becoming Dean, as well as the influence of the First World War on his career. The study draws upon unpublished material in New Zealand archives and a collection of student projects investigating public health issues. Hercus, as Professor of Public Health and Bacteriology incorporated these projects into the curriculum in the early 1920s. The thesis uses many original papers published in scientific and medical journals by Hercus and his colleagues at the School. Building on a base of archival material including contemporary newspaper accounts, which have lately become available on the Papers Past website, this thesis draws together the individual disease studies undertaken by other thesis writers to give an account of Hercus’s achievements in fostering medical research. A key finding of this thesis is that Hercus was instrumental in building up the research capability of the School. He accomplished this through his own investigations and by helping to establish the New Zealand Medical Research Council. The thesis illustrates the multitude of studies that Hercus undertook personally or facilitated others to pursue, beyond the elimination of endemic goitre, for which he perhaps is best known. Another outcome of this study is an understanding of the difficult path that scientists faced in the early years of the twentieth century in New Zealand if they wished to carry out research. This thesis follows the origins of the Department of Scientific Research in the 1920s and the frequent collaboration Hercus made with scientists outside of the School. It will also demonstrate Hercus’s compassion and foresight in employing several Jewish refugee doctors as researchers at the School, who brought expertise into the research programmes. The era was one of great interest in improving the health and wellbeing of a generation affected by wars and deprivation caused by them. A key finding of this thesis is that researchers at the School took steps to mitigate these through making New Zealand more self-sufficient in foodstuffs and to improve the national diet. As well, Hercus lobbied for the establishment of a School of Physical Education within the university to improve the physical fitness of the population.