Cor pulmonale resulting from tumor emboli is a rare presentation of gastric cancer, and only six similar cases have been reported in the English literature. We report the case of a 37-yr-old woman presenting with dyspnea who died of cor pulmonale. Autopsy revealed signet cell carcinoma of te stomach with intra-abdominal metastasis and right ventricular hypertrophy. There were no macroscopic pulmonary emboli or parenchymal lesions, but more than 60% of the small pulmonary arteries and arterioles were occluded. In most vessels, fibrocellular intimal proliferation was the major finding with only a few entrapped tumor cells.