This manual provides guidelines for working with  young men to transform norms about masculinity and unequal power dynamics that fuel the HIV/AIDS epidemic. It recommends evidence-based actions for a spectrum of program strategies, including peer-group workshops, communication campaigns, and program services, that work together to promote gender equity and reduce HIV vulnerability. Sections  include: An overview of young men’s physical, social and cultural development; educational activities; young men-friendly health services; campaigns; advocacy, and needs assessments and monitoring and evaluation. The manual’s introduction explains why engaging young men is important for HIV/AIDS prevention and highlights facts about the HIV/AIDS epidemic among youth and young men in Latin America and the Carribean.