The Canada South East Asia Regional HIV/AIDS Programme (CSEARHAP) reduced the threat of HIV/AIDS to human security and sustainable development in Southeast Asia by coordinating and enhancing responses focused on mobile populations and other vulnerable groups. The project partners improved the capacity of governments in Cambodia, Lao PDR, Thailand and Vietnam to operationalise the Regional Strategy on HIV prevention among mobile and mobility-affected populations. Coordinated responses were multi-sectoral, decentralized, focused on reducing vulnerability and co-ordinated provincially, nationally and regionally, through strategic collaboration on national and cross-border issues.