In ten patients successful embolectomy after acute massive pulmonary embolism was performed. Clinical symptoms included circulatory arrest and shock as well as collaps, syncope and dyspnoe. Pulmonary angiography regularly showed massive, bilateral emboli. In 9 patients more than one half of the pulmonary artery system was involved (perfusion defect more than 50%). Right heart catheterization demonstrated pulmonary hypertension in all cases. In 8 patients the pulmonary artery mean pressure (PAm) exceeded 30 mm Hg. In 9 patients there were signs of right heart failure (RVEDP more than 11 mm Hg). At recatheterization 6 to 30 (mean 19) days after operation using cardiopulmonary bypass there was a marked improvement of pulmonary angiograms, which were normal in 3 cases. PAm decreased from 34.3 mm Hg to 14.6 mm Hg postoperatively and RVEDP from 14.4 to 5.1 mm Hg (p less than 0.001). These results confirm, that pulmonary embolectomy leads to a good functional results.