Organophosphate (OP) pesticides cause a high morbidity and mortality in Sri Lanka due to intentional poisoning as well as accidental and occupational exposure. However exposure in the farming community and general population to OP at low levels goes unreported. Therefore the objectives of this study were to assess the health risks in farmers and the general population from low level exposure to OP pesticide in Sri Lanka and populations elsewhere using reported data and Guideline Values developed by regulatory agencies such as World Health Organization and U.S. Environmental Protection Agency. Clorpyrifos was identified as the principal pesticide of concern. The exposure was calculated in common units ng/kg body weight/day and presented as plots of cumulative probability and evaluated at the median (0.50 probability) and high (0.95 probability) exposure levels. The Guideline values of the regulatory agencies were used to characterise the health risk as Hazard Quotient. The reported TCP levels (specific metabolite of chlorpyrifos) and residue data were collected from Sri Lanka and the other countries and the exposure dose (Equivalent Chlorpyrifos Ingested Dose, ECID in ng/kg/day) and the dose in the diet (Total Dietary Chlorpyrifos Intake, TDCI in ng/kg/day) were calculated. Similarly the ECID were calculated for the international populations.