The feasibility of whole-organ transplants has received a great deal of impetus by the successful homotransplantation of the kidney in the human.1 Ever since Carrell2 described in 1908 the technical feasibility and biological aspects of such transplants, many investigators have tried to produce successful transplants. The replacement of a whole lung would be beneficial in many disease entities. The first attempt of lung transplantation using pulmonary lobes was made by Standacher and associates.3 In 1951, Juvenelle et al.4 reported the successful autologous transplantation of the right rung in the dog. After this, Neptune et al.5 Hardin et al.6 and Davis et al.7 independently reported successful homotransplantation of the left lung in the dog. Hardin and Kittle9 reported 2 survivals following left lung homotransplantation in the dog with contralateral pneumonectomy. The actual function of the homotransplant was not discussed by any of these