A serological surveillance study was conducted between March and June 2006 in the southern provinces of Cambodia to determine the prevalence and distribution of foot-and-mouth disease. Cattle and buffalo originating from eight provinces and 69 villages were sampled. The results revealed that the village level prevalence of foot-and-mouth disease (FMD) in the southern provinces of Cambodia was 87% with an overall individual animal prevalence of 30%. Three serotypes: O, A and Asia 1 were detected in this region with a prevalence of 28.5, 9.5 and 9.3%, respectively. However, as the antibody level to FMDV serotypes A and Asia 1 were generally low, it is likely that serotype O is responsible for most of the recent outbreaks of FMD in Cambodia. Seropositive animals were older than seronegative animals, especially with serotype O.