Objectives - To assess the post-epidemic seroprevalence of chikungunya virus (CHIKV), determine the proportion of symptomatic cases, and identify risk factors associated with this infection. Methods - A serological survey of 1,154 residents of Mayotte aged 2 years and older, selected using a multistage cluster sampling method, was conducted between November and December 2006. Associations between CHIKV seropositivity (presence of IgM and/or IgG measured by Enzyme-Linked Immunosorbent Assay, ELISA) and risk factors were investigated using bivariate and multivariate logistic regression analyses that accounted for the sampling design. Results - The weighted overall CHIKV seroprevalence was 37.2% (95% CI = 33.9–40.5). Among the 440 CHIKV-seropositive participants, 318 (72.3%) reported a presumptive clinical episode of CHIKV during the epidemic period. Factors found to be significantly associated with CHIKV seropositivity among individuals aged 15 years and older were: male gender, low socioeconomic status, total years of education greater than or equal to 6 years, and living in makeshift housing. Conclusion - Our results indicate that CHIKV infection was symptomatic in three out of four individuals. Reducing inequalities and rehabilitating substandard housing should be considered, alongside vector control and health education, as key components of prevention against future CHIKV epidemics. (R.A.)