P ancreatic pseudocysts are rare in pediatrics (1). They can be asymptomatic or alarming by their large size and its complications. We report a large pancreatic pseudocyst in a 13-year-old girl diagnosed on computed tomography exam 8 months after abdominal trauma. The child underwent an internal cystogastric bypass and the pathology examination confirmed the diagnosis. The objective of this observation is to describe the diagnostic aspects and therapeutic management given the data in the literature.