A method of hypofractionated accelerated radiotherapy (3 weekly fractions of 6 Gy over 2 weeks to a total tumor dose of 36 Gy) was used as single modality in 14 patients with osteogenic sarcoma for palliative treatment of the primary tumor site (six cases) or skeletal metastases (15 sites). A durable response, radiologically assessed, was obtained in 17 of the 21 (81%) irradiated sites. When this irradiation modality was combined with chemotherapy, to treat patients presenting with synchronous metastases (eight cases) or refusing amputation (five cases), a radiologically assessed response was observed in 12 of 13 (92%). In no case did a local recurrence occur before surgery or death because of progressive disease elsewhere. Of the seven patients who later had to undergo ablative surgery, a 100% and 95% tumor necrosis was observed in 6 and 1, respectively. Because of intralesional resection of primary osteogenic sarcoma after preoperative chemotherapy, seven additional patients were irradiated. None recurred at the level of the primary site. Although effective in inducing remission of osteogenic sarcoma, this irradiation method produced severe damages to normal tissues in a high proportion of patients.