Pancreatic pseudocysts in children are not uncommon. Non-resolving pseudocysts often require surgical intervention. Endoscopic cystogastrostomy is a minimally invasive procedure which is recommended for this condition. We report a large pancreatic pseudocyst in a 4-year old child, which developed following therapy with PEG-Asparaginase for acute lymphoblastic leukemia. It was managed with minimally invasive procedure.