Preoperative pulmonary evaluation is important in the management of patients with lung disease who are undergoing elective cardiothoracic or noncardiothoracic surgery. In some instances, preoperative pulmonary evaluations may also contribute to the management of patients being considered for urgent surgery. The incidence of postoperative pulmonary complications (PPCs) is high and is associated with substantial morbidity and mortality, and prolonged hospital stays. Perioperative pulmonary complications in patients undergoing elective noncardiothoracic surgery can be more accurately predicted than in patients undergoing elective cardiothoracic surgery. Effective strategies to prevent complications in the postoperative period are few. Incentive spirometry and continuous positive airway pressure are the only modalities of proven benefit. Identifying patients who are at risk for the development of PPCs and managing their underlying modifiable risk factors aggressively prior to surgery is essential.