Social Exchange Theory is one of the social science theories that have been applied to the study of human sexuality. This theoretical perspective is of particular relevance for understanding sexuality as it is negotiated between two people who have a relationship with each other. In this article, I describe three specific social exchange models with particular relevance to sexuality: equity theory (e.g., Walster, Walster, & Berscheid, 1978), the Investment Model (Rusbult, 1980(Rusbult, , 1983, and the Interpersonal Model of Sexual Satisfaction (Lawrance & Byers, 1992, 1995. Then, I discuss how the general social exchange perspective or one of the more specific exchange models/theories has been applied to five topics that focus on sexuality within a relational context: (a) partner selection, (b) onset of sexual activity, (c) sexual satisfaction, (d) sexual initiation and refusal, and (e) extradyadic sexual behavior.