Cholangiocarcinoma is an adenocarcinoma that arises from the bile duct epithelium and is the second most common primary hepatobiliary cancer, after hepatocellular cancer, with approximately 2,500 cases annually in the U.S. However, cholangiocarcinoma remains a relatively rare disease, accounting for <2% of all human malignancies. Although the entire biliary tree is potentially at risk, tumors involving the biliary confluence or the right or left hepatic ducts (hilar cholangiocarcinoma) are most common and account for 40%-60% of all cases. Most patients present with advanced disease that is not amenable to surgical treatment. The median survival time for patients with intrahepatic cholangiocarcinoma without involvement of the hilum varies among centers from 18-30 months. The median survival time for patients with perihilar cholangiocarcinoma is slightly less, varying from 12-24 months. Despite the overall poor prognosis, survival after surgical treatment of hilar cholangiocarcinoma has improved during the past 10-15 years. This review highlights the imaging features of cholangiocarcinoma, with particular emphasis on the imaging techniques that can best assess tumor resectability and guide the surgeon regarding the potential extent of resection required in operable candidates.