Background: Although acute pancreatitis is listed among the exclusion criteria for the administration of recombinant tissue plasminogen activator according to the Japanese Guideline for the Management of Stroke, the co-occurrence of acute pancreatitis and acute ischemic stroke has not been investigated. The present study aimed to assess the incidence rate of acute pancreatitis in patients with acute ischemic stroke.Methods: This study consecutively enrolled all patients with ischemic stroke admitted to the Department of Neurology, JA Toride Medical Center between April 2014 and March 2016. Diagnosis of acute pancreatitis was made according to the revised Atlanta Classification of Acute Pancreatitis. We retrospectively analyzed serum amylase activity and the frequency of acute pancreatitis as a comorbidity of ischemic stroke.Results: A total of 411 ischemic stroke patients were included. Serum amylase activity was measured for 364 patients, 27 of whom presented with amylase activity exceeding the upper limit of normal. In two patients with serum amylase activity greater than three times-fold the upper limit of normal, computed tomography or transabdominal ultrasonography showed no characteristic findings of acute pancreatitis. No patient in the cohort met the diagnostic criteria for acute pancreatitis.Conclusions: Acute pancreatitis is a very rare comorbidity of acute ischemic stroke.