The results obtained in the treatment by multimodal therapy (surgery, radiation therapy and chemotherapy) of 124 cases of Ewing's sarcoma are presented. At a medium follow-up of 65 months 48% of the patients are disease-free. One patient died of leukemia and two patients developed an irradiation-induced sarcoma. Analysing the data, three factors seem to be correlated to prognosis: location of the initial lesion outside the pelvis and sacrum, a four-drug chemotherapy protocol and the use of surgery in the treatment of the initial lesion seem to give better results.