Experience with 23 patients treated surgically, with the use of cardiopulmonary bypass, for massive pulmonary embolism is presented. Seventy-four percent survived surgery. Of the survivors all but 3 were fully recovered after observation times ranging from 3 months up to 7 years. The patient category presents the basis for our contemporary indications for surgery, i.e. patients in fulminant shock, in deteriorating clinical conditions or with contraindications for thrombolysis. In these patients surgical Intervention is recommended with the use of the heart lung machine.