A 56-year-old woman with epigastric pain was admitted to our hospital. Blood tests and abdominal computed tomography (CT) suggested acute pancreatitis. Abdominal CT revealed a pancreas divisum and stone in the minor papilla. Stone impaction was the most likely cause of the acute pancreatitis. The patient's abdominal pain promptly improved after admission. The patient was treated conservatively, and the pancreatitis resolved. Abdominal CT on the 10th day confirmed spontaneous evacuation of the pancreatic stone. This is a rare case of acute pancreatitis in a patient with pancreas divisum triggered by an impacted stone in the minor papilla, which improved after spontaneous evacuation of the pancreatic stone.