OBJECTIVE This study seeks to assess the performance of a community-based surveillance system (CBSS), developed and implemented in seven rural communes in Cambodia from 2000 to 2002 to provide timely and representative information on major health problems and life events, and so permit rapid and effective control of outbreaks and communicable diseases in general. METHODS Lay people were trained as Village Health Volunteers (VHVs) to report suspected outbreaks, important infectious diseases, and vital events occurring in their communities to local health staff who analysed the data and gave feedback to the volunteers during their monthly meetings. RESULTS Over 2 years of its implementation, the system was able to detect outbreaks early, regularly monitor communicable disease trends, and to provide continuously updated information on pregnancies, births and deaths in the rural areas. In addition, the system triggered effective responses from both health staff and VHVs for disease control and prevention and in outbreaks. CONCLUSION A CBSS can successfully fill the gaps of the current health facility-based disease surveillance system in the rapid detection of outbreaks, in the effective monitoring of communicable diseases, and in the notification of vital events in rural Cambodia. Its replication or adaptation for use in other rural areas in Cambodia and in other developing countries is likely to be beneficial and cost- effective.