The hepatic artery can have numerous variations. However, a common hepatic artery originating from the left gastric artery and the entire hepatic blood supply furnished by the left gastric artery is an extremely rare anomaly. We encountered this anomaly in a patient with advanced gastric cancer. A surgeon should recognize this image appearance and identify the anomaly. Without knowledge of this anomaly and given the strategy for extensive lesser sac dissection generally employed during gastric cancer surgery, a surgeon could easily inadvertently divide this vessel, resulting in critical liver damage. We report a case of common hepatic artery originating from left gastric artery and review of the literatures.