A series of 23 patients with carcinoma at the hilus of the bile duct were studied. Of the 23 patients, 14 underwent surgical resection. Nine of the 14 patients had a curative resection. Six patients are alive after a follow-up period of 5-25 mo. The remaining 5 patients had noncurative resection, and 4 of them died from metastatic carcinomas during the next 14 mo. One patient who had a left hepatic lobectomy is still alive 8 mo. after operation. The other 3 patients with advanced carcinoma at the hilus of the bile duct were treated by intraoperative radiotherapy. A single dose of 3000 rad was emitted directly to the tumors. The remaining 6 patients were treated by drainage procedures only. Four patients with advanced carcinoma of the gallbladder had received radiotherapy. Six of the 8 patients who were treated by radiotherapy are alive, although the follow-up period extends only to 11 mo.