Thirty-four patients with subtotally resected or unresectable carcinoma of the extrahepatic bile ducts received radiation therapy; a minimum of 45 Gy (external beam) to the tumor and regional lymph nodes +/- 5-fluorouracil (5-FU). Seventeen patients received an external beam boost of 5 to 15 Gy to the tumor, and a specialized boost was used in the remaining 17 patients (iridium-192 transcatheter seeds in 10 and intraoperative radiation therapy [IORT] with electrons in seven). The median time to death in all 34 patients was 12 months (range, 4 to 98-months). The only patients who survived longer than 18 months were those either with gross total or subtotal resection before external irradiation (2 of 6) or who received specialized boosts (192Ir, 3 of 10; IORT, 3 of 7). Local failure was documented in 9 of 17 patients who received external beam irradiation alone +/- 5-FU, 3 of 10 patients who received an 192Ir boost, and 2 of 6 patients who received an IORT boost with curative intent.