Clinically, unresectable pelvic tumor is difficult to treat because the patients have poor prognosis and often suffer from severe pain and edema of the lower limbs due to the tumor invasion of the pelvic bone and the sciatic nerve. To improve QOL of such patients, we performed thermoradiotherapy (RTHT) or internal iliac arterial infusion of 5-FU (IIAI) for 7 patients who developed unresectable pelvic tumors which relapsed after surgery for 6 colorectal cancers and one leiomyosarcoma of the uterus. The mean tumor diameter was 10.2 cm and an evaluation by computed tomography revealed 2 of 6 tumors had a partial response (PR) and 3 no change (NC). Each of the 4 patients who had been ill in bed recovered to the point of being able to walk with a cane or wheel themselves in a wheelchair after the therapy.