Incidence of PPCs varies from 2% to 19%, according to the population under examination and the criteria used to define pulmonary complications. There is no univocal definition of PPCs. Usually physicians associate atelectasis, respiratory insufficiency, pneumonia, bronchospasm, necessity of tracheal reintubation. Moreover, the evaluation of risk factors is becoming increasingly difficult. Many aspects linked to the patient's conditions and postoperative anesthesiologic management have been demonstrated to influence the risk of developing PPCs. (with the endorsement of European Society of Anesthesiology) proposed a risk index based on seven perioperative parameters to predict PPCs probability.