Brazil is renowned for its progressive and early response to the AIDS epidemic. Brazil was among the first countries to provide free and universal access to AIDS treatment. This article discusses Brazil’s evolving civil society movement related to HIV/AIDS and explains its critical role in developing Brazil’s HIV/AIDS policies and the country’s National AIDS Program. This article examines these developments in historical context and argues that the Brazilian response to the HIV/AIDS epidemic was strongly influenced by the interaction of civil society institutions with nascent democratic institutions that stemmed from Brazil’s two decadelong process of democratization. Brazil’s domestic institutions, in turn, had lasting impacts on global health institutions.