A 66-year-old man was hospitalized for diverticular bleeding of the colon. Anticoagulant drugs (Dabigatran and Beraprost sodium), which had been taken for chronic underlying atrial fibrillation, were interrupted for three days. After two months, he presented with acute pancreatitis and a pancreatic pseudocyst. The contrast-enhanced CT scan revealed an atrial thrombus and localized splenic infarction. Consequently, we suspected ischemic acute pancreatitis secondary to thrombus. Anticoagulant drug interruption and the resultant local ischemia were potential factors contributing to ischemic pancreatitis.