In 6 patients with primary malignant bone tumors (4 Ewing, 1 recurrent Adamantinoma, 1 maligne Haemangioperizytoma) the local therapy was performed as intraoperative extracorporeal irradiation and replantation. During the follow-up 10 (6-24) months no local recurrence in the replanted segment occurred. One recurrence occurred in the host bed; in two cases the replanted segment had to be removed because of severe infection. The other cases showed good functional and radiological results. These clinical findings and the reports in the literature seem to allow the application of the intraoperative extracorporeal irradiation and replantation procedure for defect reconstruction in cases of chemo- and radiotherapy-sensitive bone tumors.