Left-sided cholangiocarcinoma includes hilar cholangiocarcinoma (HC), predominantly involving the left hepatic duct, and intrahepatic cholangiocarcinoma (ICC) in the left liver. Left hepatectomy, or left hepatic trisectionectomy, is indicated as radical surgery of left-sided HC or ICC with or without hilar bile duct invasion. Left lateral sectionectomy, or left medial sectionectomy, is performed for the small mass-forming type ICC. Left hepatic trisectionectomy is indicated for left-sided HC with further cancer progress along the right anterior sectional duct or left-sided ICC involving the right anterior section over the middle hepatic vein and/or the right anterior pedicle. Combined caudate lobe and extrahepatic bile duct resection are mandatory in cases of HC or ICC involving the hepatic confluence. Preoperative biliary drainage should be performed not only for jaundiced patients but also for non-icteric patients with right-sided biliary dilatation of the future remnant liver. Preoperative left trisegment portal vein embolization after biliary drainage of the right posterior section should be carried out prior to left hepatic trisectionectomy. Left hepatectomy has been used as a radical and safer surgical procedure, but in European countries has still been associated with higher morbidity and about 10% operative mortality. Japanese surgeons have had no hospital deaths after carrying out left hepatic trisectionectomy done after preoperative biliary drainage followed by left trisegment portal vein embolization to increase safety and to prolong postoperative survival for patients with locally advanced left-sided cholangiocarcinoma.