Extracorporeal Membrane Oxygenation (ECMO) has been adopted as a means of strong respiratory support. In lung transplantation, reimplantation response is still a serious problem. It causes severe respiratory failure which is refractory to mechanical ventilation in some cases. The purpose of this study was to evaluate the effects of veno-venous ECMO after lung transplantation using a canine autotransplantation model. The autotransplantation model was created by keeping the left lung in a warm ischemic state for 2 h. After reperfusion, the right pulmonary artery was ligated. The following two groups were studied: Group 1, Control group, (no ECMO group) (n = 6). After reperfusion, both lungs were ventilated without ECMO. Group 2, ECMO group (n = 7). After reperfusion, veno-venous ECMO support was introduced with reduction of mechanical ventilation. In the no ECMO group, four of the animals died within 210 min after reperfusion. In the ECMO group, two of the animals died of severe pulmonary edema. Data of blood gas analyses (PaO2, PaCO2, and SvO2) after reperfusion were significantly better in the ECMO group, whereas there were no significant differences in both shunt fraction and pulmonary vascular resistance index. In this model with severe pulmonary edema induced by warm ischemia, veno-venous ECMO contributed to the improvement of hypoxemia and hypercapnia, but did not improve pulmonary hemodynamics.</p