A left gastric artery pseudoaneurysm is a rare complication of pancreatitis and is associated with significant morbidity and mortality. We report a 14-year-old male with severe abdominal pain and a palpable upper abdominal mass, earlier diagnosed as chronic idiopathic calcifying pancreatitis, and awaiting surgical intervention. Computed tomography showed a pseudocyst and a pseudoaneurysm in the lesser sac near the left gastric artery. The patient underwent successful angiographic coiling of the left gastric artery and definitive pancreatic surgery weeks thereafter. The early detection and interventional radiologic management of the vascular complication averted a life-threatening hemorrhage without emergency surgery in a pediatric patient.