We report a successful pediatric case who underwent combined lung and liver transplantation for a rare ectodermal dysplasia syndrome. A 5-year old boy presented with a history of haploidentical hematopoietic stem cell transplantation due to aplastic anemia and vitrectomy due to ocular tumor. When he admitted for circumcision for phimosis, oxygen saturation was 66% at 4L/min of oxygen via nasal prong. Platypnea–Orthodeoxia syndrome was observed, and a lung perfusion scan indicated hepato-pulmonary shunt, which was associated with liver cirrhosis. The patient had a pathogenic variant of dyskeratosis congenita (c.845G>A / p.Arg282His), which is known as Hoyeraal Hreidarsson syndrome. The patient deteriorated to sepsis, peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) with the configuration of the right femoral vein and right carotid artery, and renal replacement therapy was initiated. The multidisciplinary team decided to perform combined lung and liver transplantation for hepatopulmonary syndrome and liver fibrosis. Deceased donor lungs and liver were available for transplantation on day 53rd day after the initiation of the ECMO support. The donor was a 4-year-old female with identical blood type who had died from drowning. Under the peripheral veno-arterial ECMO, bilateral lungs were transplanted first, and then the liver was transplanted subsequently. The total operative time was 705 minutes. On postoperative day 4, sudden hemoptysis developed, and chest X-ray showed haziness on the left lower lung field. A chest CT scan suggested inferior pulmonary venous occlusion, which was treated by resecting the left lower lobe. The ECMO was changed from veno-arterial to veno-venous and eventually removed. Mechanical ventilator and renal placement therapy were successfully weaned off. This case is the first pediatric lung and liver co-transplantation in Korea. A multidisciprinary team approach played a pivotal role in achieving successful outcomes.