This article contributes to the cross-cultural understanding of Acquired Immunodeficiency Syndrome (AIDS) through a detailed examination of the AIDS epidemic in contemporary Brazil. Since 1983, when the first verified case was reported there, the number of AIDS victims has grown rapidly enough to place Brazil high on the list of countries with the largest number of confirmed cases. Yet the pace of this epidemic has received relatively little attention from either the international community or the Brazilian government. In addition, the model used for understanding the transmission of the disease has been developed in the rather different social and cultural contexts of Western Europe and the United States. This article draws on the author's research on Brazilian sexual culture and suggests its relevance for understanding the transmission of AIDS in Brazil. It calls for a more active and culturally appropriate response to the disease in Brazil, as well as for an increasingly sophisticated understanding of cultural differences that influence the AIDS epidemic internationally.