Three patients had coexisting pneumoconiosis and mild mitral stenosis in which pulmonary edema was the presenting clinical manifestation. Hemodynamic abnormalities seemed quantitatively insufficient to account for the degree of pulmonary edema. In spite of the mild mitral stenosis, surgical relief produced a gratifying clinical response in all three patients. The discrepancy between symptoms and the hemodynamic abnormalities was consistent with a contributory role of pulmonary lymphatic obliteration. We have attempted to define the mechanism by which coexisting pulmonary lymphatic abnormalities might alter the course of heart diseases characterized by elevations of pulmonary capillary pressure. These patients also present the opportunity to review some recent concepts concerning the mechanisms of pulmonary edema.