The authors report on a 7-year-old boy who sustained blunt abdominal trauma on a bicycle handlebar. A large traumatic pancreatic pseudocyst developed, for which percutaneous external drainage under ultrasound guidance was performed. Both the catheter fistulogram and endoscopic retrograde cholangiopancreatogram showed complete disruption of the main pancreatic duct. During continuous external drainage, the pseudocyst disappeared. The drainage flow decreased gradually and ceased. The patient is well, with normal endocrine and exocrine pancreatic functions, 2 years after discharge.