A cross-sectional study with follow-up was done in five communities involved in aquaculture in peri-urban Phnom Penh, Cambodia, to assess the association between skin disease, particularly dermatitis and occupational wastewater exposure. From 200 selected households 650 household members aged≥15 years were visited and examined dermatologically three times in July 2004, January and May 2005. Overall dermatitis prevalence was 6.1%. However, all cases (116) were found in the two wastewater villages involved in aquatic plant culture. Risk factor analysis restricted to the two wastewater villages showed that involvement in wastewater-fed aquatic plant production increased the risk of dermatitis in the univariable analysis but not in the multivariable analysis. Among family members involved in wastewater-fed aquatic plant production a longer duration of daily wastewater contact did not increase the risk of dermatitis in the multivariable analysis. Wet season, older age and having a history of skin problems in the three months prior to each survey were associated significantly with dermatitis. Very few aquaculture workers applied personal protection and the factor had no significant effect on dermatitis. The present study did not show a consistent association between occupational exposure to wastewater and dermatitis, unlike similar Vietnamese studies.