This article describes the design, implementation, and evaluation of a sexual-risk prevention program focused on the development of individual competencies and cultural norms promoting healthy sexual decision making. The community-based peer-facilitated intervention targeted adolescents and young adult men and women in Sri Lanka, who participated in small-group activities targeting sexual knowledge, attitudes, and practices; risk perception; and sexual-risk decision making. The intervention and evaluation tools were based on formative research data collected from members of the target population. Researchers from Sri Lanka and North America collaborated with local community health workers and community members in formative data collection and program development. The pilot intervention project was successful in improving sexual-risk perception and decision making, and (for women) knowledge of condoms and sexual terminology. The use of group process showed promise as a tool for fostering negotiation of perspectives and consensus building regarding sexuality and sexual risks. The lessons learned from this project can inform the development of culture-specific sexual-risk prevention programs worldwide.