Sixteen consecutive patients with anaplastic carcinoma of the thyroid were prospectively treated according to a combined regimen consisting of hyperfractionated radiotherapy, doxorubicin and debulking surgery. The radiotherapy was preoperatively administered to a target dose of 30 Gy in 3 weeks, and postoperatively to an additional dose of 16 Gy in 1.5 weeks. Radiotherapy was administered twice daily, 5 days a week, with a target dose of 1 Gy per fraction and with a minimum interval of 6 hours. A dose of 20 mg doxorubicin was administered intravenously 1 to 2 hours before the first radiotherapy session every week. Debulking surgery was feasible in 9 patients. Local complete remission was achieved in 5 patients and 3 of these are still alive disease-free at 10, 30, and 30 months respectively after diagnosis. Only 6 patients succumbed to a local failure. This combination regimen was well tolerated despite the patients' high age and advanced disease.