The reverse Potts shunt is increasingly used as a palliative measure for end-stage pulmonary arterial hypertension (PAH) as a means to offload the right ventricle and improve functional status. This case report describes a child who developed significant hemothorax after reverse Potts shunt that required surgical exploration, blood product administration, and prolonged intensive care hospitalization. Despite lack of preoperative bleeding symptoms, testing revealed acquired von Willebrand disease (aVWD), with subsequent resolution of bleeding. Alterations in von Willebrand factor, including aVWD, have been reported in children with severe PAH but have not previously been associated with bleeding after reverse Potts shunt procedure. As bleeding is a recognized postoperative morbidity in PAH patients undergoing reverse Potts shunt, we highlight a potential role for preoperative testing for aVWD as perioperative factor replacement therapy may improve postoperative outcomes.