Because of its slow‐growing natural history, most patients with extrahepatic biliary tree malignancies present with inoperable disease. For the minority of patients with operable disease, surgical resection remains the treatment of choice and offers the patient the best chance for long‐term local control. The role of chemotherapy and radiotherapy in the management of these patients in the definitive, adjuvant, and palliative setting is expanding, although unsettled. Response rates with chemotherapy have been low and will most likely find a place in a combined multimodality setting. Radiotherapy (external beam, intraoperative, and intraluminal brachytherapy using 192Ir) has played a major role in the treatment of these cancers. The close proximity of bowel, kidney, and liver limits the external beam radiotherapy doses that can be safely delivered. Since most patients require placement of percutaneous transhepatic biliary catheters to relieve jaundice, this route has been utilized to deliver higher doses of radiation to the tumor area with intraluminal 192Ir ribbons. The University of Minnesota has treated 15 patients with extrahepatic bile duct cancers. Most were located at the bifurcation of the common bile duct and were treated with intraluminal brachytherapy alone or with external beam radiotherapy. Our results are comparable to previously reported retrospective data with a median survival of 8 months and three long‐term survivors. J. Surg. Oncol. 1997;65:298–305. © 1997 Wiley‐Liss, Inc.