Biliary tract cancer affects approximately 7500 Americans each year. Tumors arising from the gallbladder are the most common; those of bile duct origin, or cholangiocarcinoma, are less frequently encountered, constituting approximately 2% of all reported cancers. Although cholangiocarcinoma can arise anywhere within the biliary tree, tumors involving the biliary confluence (i.e., hilar cholangiocarcinoma) represent the majority, accounting for 40 to 60% of all cases. Twenty to 30% of cholangiocarcinomas originate in the lower bile duct, and approximately 10% arise within the intrahepatic biliary tree and will present as an intrahepatic mass. Complete resection remains the most effective and only potentially curative therapy for cholangiocarcinoma. For all patients with intrahepatic cholangiocarcinoma and nearly all patients with hilar tumors, complete resection requires a major partial hepatectomy. Distal cholangiocarcinomas, on the other hand, are treated like all periampullary malignancies and typically require pancreaticoduodenectomy. Most patients with cholangiocarcinoma present with advanced disease that is not amenable to surgical treatment, and even with a complete resection, recurrence rates are high. Adjuvant therapy (chemotherapy and radiation therapy) has not been shown clearly to reduce recurrence risk.