Cor pulmonale is defined as an alteration in the structure and function of the right ventricle caused by a primary disorder of the respiratory system. There are three major groups of respiratory diseases causing chronic cor pulmonale obstructive lung diseases, restrictive lung diseases and respiratory insufficiency of central origin. Physical findings may show the features of underlying lung disease along with the features of pulmonary hypertension, right ventricular hypertrophy (RVH) and/or right ventricular (RV) failure depending upon the severity and duration of the disease. Its complications include syncope, hypoxia, pedal edema, congestive cardiac failure and death. The outcome depends more on the treatment and management of the underlying lung disease than on cor pulmonale itself.