Although the incidence of occupational and adult lead poisoning has declined, the problem still exists. We encountered three patients with lead poisoning in Iran, all of whom associated with presented with diffuse abdominal pain, which was at times colicky in nature, anemia, constipation, nausea, vomiting, and slightly abnormal liver biochemistries. A history of opium ingestion was present in each of these patients. None of the patients reported known occupational exposure to toxins. Diagnoses of lead poisoning were confirmed through the detection of elevated blood lead levels. The cause of lead poisoning was attributed to the ingestion of contaminated opium. Opium adulterated with lead had not been previously recognized as a source of lead poisoning in Iran. It is, therefore, pointed out that lead poisoning should be considered as a differential diagnosis for acute abdominal colic of unclear cause in patients with opium addiction.