The essay presents a biographical case study devoted to Antonio Savaresi (1773-1830). This Neapolitan military physician, who had arrived in France as republican exile, served in the French armies in Egypt, Martinique and Italy, where he had to cope with plague, ophthalmia and yellow fever epidemics. Reconstructing Savaresi’s biography and analysing his writings allows examining medical thought and practices during the French revolutionary and Napoleonic wars. The article tackles the process though which scientific knowledge is constructed, focusing on strategies of scholarly self-legitimation, on the combination of European medical doctrines and non-European therapeutic practices, as well as on the links between medicine and racial anthropology.