A 17-year-old boy with Gaucher's disease died suddenly 2 days after femoral osteotomy. At autopsy, in addition to extensive infiltrates of Gaucher cells in the cirrhotic liver, lymph nodes, and bone marrow, there were high-grade pulmonary arterial hypertensive changes but virtually no Gaucher cells in the lung. Although previous reports have stressed lung infiltrates with capillary plugging by Gaucher cells as important in the pathogenesis of pulmonary hypertension, the present case raises the question of a different mechanism--possibly a circulating vasoactive substance that bypasses the diseased liver.