Left-sided gallbladder is a rare anomaly that is often associated with other abnormal anatomy in the hepatobiliary system. We report our experience of a case of left-sided gallbladder associated with the congenital hypoplasia of the left lobe of the liver. A 71-year-old woman underwent cholecystectomy for acute cholecystitis. Intraoperative findings revealed the absence of the left lobe of the liver. The gallbladder was located in the left side of the round ligament, which was associated with abnormal intrahepatic portal branching. The incidence of left-sided gallbladder without situs inversus is very rare. The following anomalous anatomy associated with left-sided gallbladder should be a concern when a surgeon encounters a left-sided gallbladder: right-sided round ligament associated with abnormal intrahepatic portal branching and ectopic gallbladder attached to the left lobe of the liver that connects to the left hepatic duct via the cystic duct or the accessory bile duct.