Cambodia is one of the few countries in the world to achieve the MDG in reversing the spread of HIV, with the prevalence falling from 3% in 1998 to 0.7% in 2008. The decline indicates a high commitment from government and civil society in the fight against HIV. The book highlights the success in multiple interventions and challenges facing over the course of the epidemic. The work is based on different studies conducted over the course of preventive interventions from 2002 to 2005 to investigate the epidemiological context of the epidemic, and how this is related to changes in risk behaviours in the general population and in sub-groups of the population. Results from this work suggest an optimistic future in HIV control and prevention in Cambodia. However, challenges do remain, including the reliable quality of HIV/STI service deliveries, the sustainability of preventive programmes, and the dependency of heavily external funding supports. This book should be useful for students and professionals in public health especially for program planners and researchers, or anyone who may be interested in the development of HIV prevention and control in developing countries.