Biliary endoprostheses (EMBE) using expandable metallic stents or intracavitary irradiation with remote afterloading (RALS) were carried out in eighteen patients with malignant biliary obstruction. There were 11 patients with bile duct cancer, 3 patients with gallbladder cancer, 2 patients with pancreas cancer and 2 patients with metastatic gastric cancer. The favourable results were obtained. Placement of stents was successful in all 17 cases in which the EMBE was conducted, and in all cases but one, the duct was cleared. At the follow-up of 2 to 59 weeks, all stents maintained patency and there were no severe complications, although only one patient had jaundice due to obstruction at the stented duct 4 months after EMBE. In nine cases, intracavitary irradiation with RALS was performed using a newly developed 14 Fr applicator. The bile duct walls at the irradiation site were smooth and expansion of the constricted area was seen. These results indicate that the combined use of EMBE and intracavitary irradiation with RALS could form a new part of treatment of malignant tumors of the bile duct in which radical surgery is not possible.