The results obtained in 172 cases of non metastatic Ewing's sarcoma of the extremities are reported. The patients were advised to undergo surgical treatment, followed by radiotherapy (40-45 Gy) in case of inadequate surgical margins. 48 patients who refused surgical treatment, were locally treated with radiotherapy alone (50-65 Gy). With a mean follow-up of 8 years (R. 3-15) 101 patients (58.7%) are free of disease and 68 relapsed with metastases and/or local recurrence. A radio-induced bone sarcoma developed in two patients, one patient died of ADM cardiomyopathy. No differences in terms of risk factors were observed between patients who were or were not treated with surgery. A better DFS was observed in the patients treated with surgery (66.9%) in comparison with those treated with radiotherapy alone. The higher percentage of local recurrences observed in patients treated with radiotherapy alone seems to be responsible for the worse prognosis observed in these patients. The authors' conclusion is that the local control in patients with non metastatic Ewing's sarcoma should always be achieved by means of surgery.