The economic and social impacts of Foot and Mouth Disease (FMD) for livestock owners in developed countries have been extensively documented over the past few years. In developing countries like Cambodia, the lack of accurate data makes it difficult to evaluate FMD perception by local communities and its current impact at household level. In this study, we decided to use a range of participatory tools in order to assess the knowledge, the perception and the 2009 relative incidence of FMD in 51 villages in the Svay Rieng province of Cambodia. The detection of antibodies directed to the non-structural FMD virus proteins (NSP) at village level was used to cross-validate results from participatory epidemiology. Matrix scoring agreements of pair-wise disease ranking and losses due to FMD, respectively W=0.13 and W=0.22 P<0.0001, showed a significant importance and similar perception of FMD for all districts visited. The average disease relative incidence for all species at village level for 2009 was evaluated by proportional piling at 12% [Min-Max 0-46]. The observed proportions of positive agreement between both serological and participatory approaches for 2009, varied between 42% for village status and 68% for animal status. Our study shows that even if FMD is considered as the second most important disease, livestock owners see no benefit in reporting it since the disease is known to have low direct impacts. Participatory methods have proved useful in evaluating the effect of FMD at household level but seem to overestimate the presence of the disease.