The authors present the case of a 12-year-old boy with a history of chronic upper abdominal pain. Based on ultrasonography, endoscopic retrograde cholangio-pancreatography, and computerized tomography, a diagnosis of chronic calcific pancreatitis with dilation of the main pancreatic duct and a pseudocyst of the proximal pancreas was made. At surgery, in addition to confirmation of the above findings, a pseudoaneurysm arising from the splenic artery was found in the head and body of the pancreas. Pancreaticoduodenal resection including the pseudoaneurysm was performed. Postoperatively the child developed diabetes, which is easily managed with small doses of insulin.