We present the case of a 9-year-old boy with portal hypertension who died suddenly and unexpectedly due to pulmonary hypertensive crisis during a routine endoscopic procedure. He had known portal hypertension with esophageal varices but had no preceding clinical symptoms suggestive of significant pulmonary hypertensive disease despite postmortem histological evidence of advanced pulmonary vascular changes. Portopulmonary hypertension is a well-described and distinct clinical syndrome that is rare in childhood and is associated with a relatively poor prognosis. Occasional patients with histologically advanced disease may remain asymptomatic but present with pulmonary hypertensive crisis. Children with portopulmonary hypertension should be considered at high risk for surgical procedures, and pulmonary hypertensive complications should be excluded as a cause of death in all children dying suddenly in the setting of portal hypertension.