Purpose: Hemoperfusion is an effective modality of extracorporeal elimination of toxins in acutely poisoned patients. We evaluated the effect of hemoperfusion on plasma concentration of toxins in patients exposed to certain pesticides. Methods: Eleven patients who were acutely exposed to pesticides participated in our study. We measured plasma pesticide concentration from the whole blood obtained by arterial and venous sources by gas chromatography. Results: The plasma concentrations of only 3 patients was measured. Methidation clearance by hemoperfusion was 82.2%, fenitrothion was 23%, and endosulfan was 0% Conclusion: Measurement of plasma organophosphate concentration is not a practical application. Our results suggest that hemoperfusion is applicable in patients with pesticide intoxication according to clinical status.