Gastric cancer among coal miners is reviewed and a hypothesis is provided to explain the elevated incidence of gastric cancer mortality among United States coal miners, and a more than 3 fold increase in gastric cancer incidence has been identified. However, the etiology of the cancer in humans is not known. Inhaled dust particles cleared from the lungs can be swallowed and introduced into the stomach. A greater stomach burden has been suggested to exist for inhaled dust particles than the ingested dust particles. Many organic chemicals used in foods are preserved by nitrites or nitrates. Under acidic conditions, as exist in the stomach, many organic chemical constituents of food can be nitrosated. The formation of mitogenic and carcinogenic nitrosamines from reactions of secondary amines and nitrite under acidic conditions has been documented in-vitro and in-vivo. Highly carcinogenic compounds are generated by a combination of tobacco smoking and ingestion of food containing many organic and inorganic chemicals. Although coal dust is not carcinogenic, carcinogenic compounds may be produced in the stomach by enzymic or nonenzymic nitrosation or through interaction with other exogenous chemicals. The carcinogens thus produce attack epithelial cells and induce precancerous lesions in the stomach. Evidence for the above hypothesis was obtained from a review of literature and several NIOSH studies. The authors conclude that carcinogens produced in the stomach from coal mine dust, either through intragastric nitrosation or through reaction with other chemicals, are responsible for the cancer excesses in underground coal miners.