As the HIV/AIDS epidemic continues its relentless spread in many parts of the world, DOI provides a useful framework for analyzing the difficulties in achieving behavior change necessary to reduce HIV rates. The DOI concepts most relevant to this question include communication channels, the innovation-decision process, homophily, the attributes of the innovation, adopter categories, and opinion leaders. The preventive measures needed to halt the transmission of HIV constitute a ‘‘preventive innovation.’’ This article describes the attributes of this preventive innovation in terms of relative advantage, compatibility, complexity, trialability, and observability. It reviews studies that incorporated DOI into HIV/AIDS behavior change interventions, both in Western countries and in the developing world. Finally, it discusses possible reasons that the use of DOI has been fairly limited to date in HIV/AIDS prevention interventions in developing countries.