This issue of Surgical Oncology Clinics of North America is devoted to "Biliary Tract and Primary Liver Tumors" and is edited by Timothy Pawlik, MD, of the Johns Hopkins Hospital in Baltimore. Expert authors in this issue review this topic in articles such as: Epidemiology and Risk Factors of Biliary Tract Tumors and Primary Liver Tumors; Imaging of the Patient with a Biliary Tract or Primary Liver Tumor; Percutaneous and Endoscopic Approaches to Biliary Tract Tumors and Primary Liver Tumors; Intrahepatic Cholangiocarcinoma; Hilar Cholangiocarcinoma; Distal Cholangiocarcinoma; Hepatocellular Carcinoma; Staging of Biliary Tract and Primary Liver Tumors; Intra-arterial Therapies: Primary Liver Tumors; Radiotherapy: Primary Liver Tumors; Systemic and Targeted Therapy; and Palliation: Treating Patients with Inoperable Biliary Tract and Primary Liver Tumors.