An 8-year-old boy presented with abdominal pain and poor oral intake for two months. Serum amylase and lipase levels were elevated. CT of the abdomen and chest X-ray showed two pseudocysts at the pancreatic uncinate process, pancreatitis with a parenchymal defect, a large amount of ascites, and a right pleural effusion. MR cholangiography and endoscopic retrograde cholangiopanreaticography revealed a pancreatic duct disruption. The patient was successfully treated with a chest tube placement and percutaneous drainage. After surgery, his general condition improved; the serum level of amylase normalized and the pleural effusion resolved. Pancreatic injuries are rare in pediatric blunt trauma; however, diagnostic difficulty is common with isolated blunt trauma. Therefore, a high index of suspicion should follow such an injury. We report the case of an 8-year-old boy with pancreas transection, ductal disruption, ascites, and pleural effusion who was successfully treated.