This article is a review of 22 cases of Ewing's sarcoma peripheral to the elbow and knee treated with moderate dose radiotherapy, with special reference to local control, functional result and risk of irradiation induced sarcoma. Eleven patients (50%) are alive two to 16 years following radiotherapy. Two of these had local recurrences, one being salvaged by reirradiation and the other by amputation. The functional results of treatment were assessed in the nine survivors who did not have a recurrence . Eight had normal limb function and one had a 3 cm leg-length discrepancy. Nine patients in the total experience of the hospital who survived more than ten years after radiotherapy were assessed for evidence of postirradiation sarcoma and none were found. The excellent results of radiotherapy in terms of local control, function and lack of irradiation induced sarcomas is attributed to the use of moderate doses of irradiation.