The French colonization of nineteenth century Vietnam occurred at a moment when the domination/exploitation of the country coincided with the triumph of biomedicine in European health policies and the growth of the Western pharmaceutical industry. In this context, an analysis of the roles of traditional sino-vietnamese medicine affords an excellent opportunity to examine the meeting of two very different medical systems. Although at first denounced by colonial authorities and French doctors as a deadly poison to be avoided at all costs, over time, the continuing presence of sino-vietnamese medicine in French-dominated Vietnam came to reveal variety of practices and realities associated with a complex and ambiguous medicalization process, one very difficult to control from above. The vestiges of this ambiguity remain visible in multicultural Western societies and in Asian societies even today.