In a total number of 44 patients with acute massive lung embolism 42 patients survived the acute phase. The treatment was carried out by thrombolysis with streptokinase. The application was performed as near to the thrombus as possible, in several patients after preceding balloon dilatation or also as multiphase treatment using urokinase. We altogether obtained favourable early results concerning the recanalisation got as well as also with regard to the clinical state and the subjective condition, particularly for patients with single acute occurrence and a latency period of less than 72 hours up to the beginning of the treatment. In follow-up examinations of 17 patients after more than 9 months (on an average after 32 months) without exception a good and further on ameliorated condition, respectively, was stated. Under long-term anticoagulation with phenprocoumon no recidivation embolisms appeared. Ergooxytensiometric investigations had as result a clear to extreme hypoxia on exertion as limiting factor for 12 out of 17 patients. Apart from this the majority of the patients a hyperdynamic regulatation of the circulation was to be observed. Therefore the ergooxytensiometry is recommended for the judgment of the result of the treatment as to the demandable exercise tolerance.