Organophosphate poisoning is well known for its characteristic symptoms and signs, but food poisoning caused by pesticide-contaminated food is seldom reported. We report three incidents of food poisoning that resulted from exposure to the organophosphate insecticide methamidophos in vegetables. These outbreaks caused a cholinergic syndrome in 4 patients. The cholinergic overactivity led as to suspect organophosphate food poisoning. All patients recovered well following appropriate therapy. The clinical diagnosis of organophosphate poisoning was confirmed by reduced levels of erythrocytes and plasma cholinesterase and the presence of methamidophos in the vegetable leftovers. The implicated vegetables and levels of methamidophos were: Ipomoea batatas 255 ppm, Gynura bicolor 110 ppm, and red cabbage 26.3 ppm. Since methamidophos is normally applied to vegetables during planting, improper selection and/or overuse of pesticide or improper harvest times may explain the occurrence of these high residue levels of methamidophos.