During the period from 1961 to 1981, 40 pulmonary embolectomies were performed in 39 patients who were in extremis at the time of initiation of cardiopulmonary bypass. In a 460-bed hospital with more than 17,000 acute admissions and 4,000 operations per year, this small number represents the few patients who are potentially salvageable by urgent embolectomy. Preoperative angiography was performed in 57% of the cases, and in another ten patients suspected of having pulmonary emboli, angiography prevented unnecessary thoracotomy. Despite their moribund condition, 43% of the embolectomy patients lived. Excluding two patients with tumor occlusion of the pulmonary arteries and three patients with chronic cor pulmonale from old pulmonary emboli, the survival rate was 50%. Ten patients died because of hypoxemia and hypotension prior to initiation of cardiopulmonary bypass, and seven died of myocardial depression of multiple etiologies. Portable cardiopulmonary bypass affords the possibility of survival in moribund patients with acute massive pulmonary embolism. Preoperative angiography is recommended to guide appropriate surgical management.