Osteoblastic osteosarcoma in the distal radius of a 50-year-old woman was treated by en bloc resection, intraoperative extracorporeal irradiation, and reimplantation. Twenty-three months after surgery finger function was good. No tumor recurrence or distant metastasis was found at the final follow-up examination. Intraoperative extracorporeal irradiation and reimplantation is an easy and convenient reconstructive surgical procedure after en bloc excision of a tumor in the distal radius. A biologic reconstruction with a precise anatomic fit is possible, and long-term endoprosthetic problems and maintenance of bone-banking facilities for allografts are avoided.