South Africa and Trinidad and Tobago are disproportionately impacted by high rates of HIV/AIDS among adolescents.The article describes the HIV crises in these countries; outlines a community participatory research framework to adapt and deliver family-based prevention; and presents preliminary data from intervention pilots in each setting.Adapted interventions were piloted with N = 140 families in South Africa and N=16 families in Trinidad and Tobago to refine recruitment and retention efforts and to assess the adapted interventions' impact on family and risk-related constructs.Both settings reported promising results including high recruitment and retention and favourable pre to post changes in parent/youth frequency and comfort in talking about sensitive subjects, HIV transmission knowledge and attitudes about persons with HIV/AIDS.International HIV-prevention alliances are increasing. Such alliances are challenged by trust issues, power-differentials and ideological differences. Recommendations are provided on how some challenges can be overcome.