We have experienced a patient complaining of the prolonged pain after left hepatectomy. The patient was a 53-year-old man. He underwent left hepatectomy for cholangiocellular carcinoma, and complained of prolonged abdominal pain for more than 10 days after the operation. After detailed examinations, we noticed duodenal perforation. After the conservative treatment, his pain was improved. In this case, the causes of the prolonged pain might be peritoneal irritation caused by gastric contents and duodenal perforation. The peritoneal irritation was caused by bile leakage and the deformity of the stomach that might be due to the enlarged dead space after left hepatectomy. We should be cautious of possible pyloric obstruction as the cause of prolonged pain after left hepatectomy.