The results of direct pulmonary embolectomy in 20 cases of pulmonary embolism treated in our facility from 1982 to May, 1995 was analyzed. The ages of the patients ranged from 25 to 72 years (mean: 46 years). The male-to-female ratio was 12:8. The 20 cases were divided into three groups based on the type of pulmonary embolism: Group I (4 cases of acute massive pulmonary thrombo-embolism). Group II (12 cases of chronic pulmonary thrombo-embolism) and Group III (4 cases of tumor embolism). In Group I, 2 patients developed shock and 2 developed severe right heart failure. Emergency thrombectomy using cardiopulmonary bypass succeeded in saving the lives of 3 patients in this group. In Group II, the preoperative NYHA grade was II in 1 case, III in 9 cases, and IV in 2 cases. The preoperative systolic pressure of the pulmonary artery ranged from 24 to 90 mmHg (mean: 74 mmHg). Surgery through a thoracotomy was carried out on 7 cases (on the right side in 4 cases on the left in 3 cases). Of these 7 patients, 2 died of heart failure and respiratory failure because thromboendarterectomy was inadequate. In another 2 patients, symptoms improved enough to allow them to resume their previous lives. The other three patients showed no change in their symptoms after surgery, but they could be discharged. The remaining 5 patients in Group II underwent surgery through the median approach. Deep hypothermia with circulatory arrest was used in the latter 4 of these 5 patients during surgery. 3 patients died during the perioperative period because adequate thromboendarterectomy was not possible and because their preoperative condition was very poor. 2 patients who were able to be performed adequate thromboendarterectomy showed good postoperative courses. Of the 4 patients in Group III, one patient survived 11 months after surgery, but the other 3 died during the preoperative period because very little embolus could be removed. These results allow us to conclude that the lives of patients with acute pulmonary thromboembolism can be saved by early detection and prompt surgery, but that management of chronic pulmonary thromboembolism involves difficulties in selecting surgical cases and in performing thromboendarterectomy.