Today, there are few effective treatment options to unresectable hepatobiliary cancers. We enforced chemoradiotherapy to 7 patients who had far advanced hilar cholangiocarcinomas or hepatobiliary cancers because they could not receive radical operations. Then, we examined the effectiveness of this therapy. The radiation method was a conformation radiotherapy to 5 patients and the combination of conformation radiotherapy and RALS to 2 patients irradiated once with the radiation of 2-3 Gy. The menu of chemotherapy was the combination of 5-FU (1,250 2,500 mg/week) and CDDP (10-50 mg/week) by intravenous infusion or injection to the hepatic artery in all patients. By this therapy, 6 out of 7 patients were able to live for one year or more, and the median survival time was 1.41 years (0.65-2.65). Only two patients were judged as clinical PR by computed tomography, but the value of the tumor marker after radiotherapy was 85.7% (6/7), a decrease of 1/3 or less before the treatment. As for side effects, nausea, vomit, and appetite loss were observed in some patients. However, they were not so severe and the treatment could be easily restarted. Though various examinations are necessary, the chemoradiotherapy is expected to be useful for unresectable hepatobiliary cancers.