The process of linking sexual and reproductive health and HIV/AIDS needs to work in both directions: traditional sexual and reproductive health services need to integrate HIV/AIDS interventions, and programmes set up to address the AIDS epidemic need to integrate more general services for sexual and reproductive health. The case studies featured in this series have been chosen to demonstrate this two-way flow and to reflect the diversity of integration models. While these case studies focus primarily on service delivery components, structures, systems and policy issues are also important elements of successful integration.