During an epidemic of Weil’s disease amongst north Queensland cane cutters in the 1930s medical debates over whether it was contracted in the fields; how the disease should be controlled; whether clinical diagnosis alone was sufficient; and whether there were long-term effects from it were not value free. Rather, they were influenced by wider social, political and economic concerns of the time. Dr Raphael Cilento, Director General of Health and Medical Services, embraced a more conservative approach to these questions, clashing with the local doctor Gordon Morrissey. As head of the health department, Cilento’s opinions on malingering workers, migrants and the economic importance of the sugar industry influenced public policy decisions relating to workers’ compensation as well as the government’s approach to controlling the disease. The Weil’s disease epidemic reveals that medical and scientific knowledge and research, while projecting an aura of objectivity, often mask social/subjective elements.