This study was conducted to answer the question, "Are sexual risk behaviors subject to compensation?" For example, do people who increase their use of condoms compensate for this reduction in human immunodeficiency virus and sexually transmitted disease (HIV/STD) risk by engaging in more overall acts of intercourse or by having sex with more partners than before? Utilizing the HIV prevention literature, studies in which participants demonstrated sexual risk compensation were identified. A simple HIV/STD transmission model was applied to these data to determine whether compensation produced a net increase in HIV/STD risk, despite positive changes in one or more aspects of sexual behavior. Although a number of studies were found in which there were simultaneous increases in condom use and the overall number of acts of intercourse, in none of these instances was there an overall increase in HIV/STD risk. Moreover, none of these studies reported concomitant increases in the number of sex partners. Extensive modeling exercises also were conducted to determine the theoretical conditions under which compensation would produce a net increase in risk. The results of the modeling exercise indicated that relatively small increases in overall sexual activity could be sufficient to offset risk-reduction gains due to increased condom use in populations in which baseline condom use is very low. In sum, although sexual risk compensation occurs, no empirical evidence was found that this compensation is sufficient to offset reductions in risk due to greater condom use, despite the theoretical plausibility of this scenario.