Chemoradiotherapy using cisplatinum (CDDP) as the X-ray intensifier was performed on patients with urothelial carcinoma. Ten lesions in 9 patients, 6 patients with postoperative relapse and 3 who received the therapy as a palliative treatment for progressive carcinoma, were evaluated. Four of the patients with postoperative relapse had undergone adjuvant chemotherapy. On the day of the treatment, the 9 patients were given continuous intravenous infusion of CDDP at the dose level of 5-12 mg/day prior to external irradiation at 50-66 Gy. The response to the therapy was categorized as complete response in 5 patients, partial response in 4, and no change in 1. The response rate was 90%, indicating achievement of a good local control. Pain relief and improvement of hydronephrosis were also observed in patients who underwent the therapy for treatment of progressive carcinoma. All adverse reactions were mild in intensity. These results suggest that the chemoradiotherapy is useful for both patient groups, those who have a postoperative relapse and those who undergo the therapy as a palliative treatment for progressive carcinoma.