Although the incidence of pneumonectomies is decreasing all around the world, it is still required in centrally located tumors and in case of destroyed lung secondary to benign diseases. In a normal person, right lung contributes 55% of lung function due to the presence of three lobes. It is well known that remaining lung tissue expands its alveolar capacity following pneumonectomy. This compensatory growth has been attributed to stimulus by shear stress which leads to pulmonary fibroblast differentiation and neoalveoalization. Pneumonectomy results in progressive deterioration of lung function (around 30%) over the years. This leads to an increase in pulmonary artery pressure and right ventricle workload.Elderly patients with preexisting pulmonary diseases are especially at risk. On the other hand, pediatric pneumonectomies under the age of five lead to a near normal pulmonary function. There are also effects on esophagus and main bronchi due to anatomic changes in the chest cavity. However, most of the pneumonectomized patients do not experience limitations in normal life. Pneumonectomy should be avoided whenever possible if an oncologically correct operation can be performed with a lesser resection.