Pancreatoblastoma is an extremely rare tumor in children, especially under 3 months of age. This tumor may arise from any portion of the pancreas, but in more rare cases the ectopic pancreas is the origin. We are reporting a 3-month-old boy who was presented with an abdominal mass. Computed tomography images revealed a huge lobulated mass anterior to the kidneys, with internal calcification and enhancement after intravenous contrast media injection. He underwent a complete surgical resection of the mass that was located in the transverse mesocolon without any connection with the pancreas. Pathologic studies specified that the disease was pancreatoblastoma. His parents refused any chemotherapeutic regimen but continued postsurgical follow-ups.