Curtailing the human immunodeficiency virus (HIV) epidemic requires the development of effective strategies for helping people reduce high-risk sexual behavior patterns. Because the objective of HIV prevention involves changing how people behave sexually, research findings in human sexuality are extremely pertinent to efforts to promote AIDS risk reduction. Unfortunately, most public health HIV prevention programs rarely reflect findings of human sexuality research. In this article, research is reviewed in the areas of the relationship contexts of sexuality, including variations in monogamy, condom use in affectionate versus casual relationships, sexual communication, and coercion; the modification of sexual behavior repertoires; substance use in relation to sexual intercourse; and sexual schema and scripts relevant to HIV risk. Policy and training issues related to human sexuality may have hindered efforts to incorporate sexuality research findings in HIV prevention programs. Advances and refinements in the success of HIV prevention efforts are likely if research on human sexuality is better integrated in AIDS prevention programs.