Although 82,5% of the total body weight consist of mesenchymal tissues, only 1%--3% of all malignant tumors are soft tissue sarcomas. The necessary irradiation dose can only be determined after an exact histopathological diagnosis; therefore this diagnosis has to be made prior to the radiotherapy. Except the fibro- and liposarcomas, all sarcoma form very early lymphogenic metastases. All sarcomas show a remarquable tendency to form recurrences. Surgery is the primary therapy. After that, an irradiation of the tumor region and the regional lymph nodes should be effected under all circumstances. We have treated and checked up 749 patients. After this therapeutic method, the five-year survival rate in the stages T1 and T2 is 60% for the myxosarcoma, 67% for the angiosarcoma, 41% for the fasciculated sarcoma, 40% for the globocellular sarcoma, 30% for the polymorphous sarcoma, 69% for the fibrosarcoma, and 61% for the leiomyosarcoma.