We present a retrospective analysis of seven patients with chondrosarcoma of the bone treated by high-energy irradiation between 1961 and 1976. Its major role in this series was prevention of local recurrence in cases with inadequate resection. In three of the five cases in which radiation therapy was adjuvant rather than primary treatment, long-term local control was obtained in a dose of 5,000 to 6,500 rads in five to six weeks. Although primary treatment of chondrosarcoma is surgical, high-dose radiation therapy is indicated when surgical resection is not possible. Chondrosarcoma can respond to high doses of irradiation even though the response is slow.