Previous research has questioned the effectiveness of existing methods to identify individuals at high risk for contracting and transmitting human immunodeficiency virus and other sexually transmitted diseases. Thus, new approaches are needed to provide these individuals with risk-reduction strategies. We review our research on young adults' sexual decision making by using theories and methods from social and cognitive sciences. Four patterns of condom use and associated levels of risks and beliefs were identified. These patterns suggest value in targeting intervention strategies to individuals at different levels of risk. The findings also imply that the monogamous population may be at higher risk for infection than they realize. Primary-care physicians are the first line of contact for many individuals in the health care system and may be in the best position to screen for at-risk individuals. Given the time demands and other barriers, easy-to-use, evidence-based guidelines for such screening are needed. We propose such guidelines for primary-care physicians to use in identifying an individual's risk, from which custom-tailored intervention strategies can be developed.