Postoperative pulmonary complications play an important role in the risk for patients undergoing noncardiothoracic surgery. Postoperative pulmonary complications are as prevalent as cardiac complications and contribute similarly to morbidity, mortality, and length of stay. Pulmonary complications may even be more likely than cardiac complications to predict long-term mortality after surgery. The purpose of this guideline is to provide guidance to clinicians on clinical and laboratory predictors of perioperative pulmonary risk before noncardiothoracic surgery. It also evaluates strategies to reduce the perioperative pulmonary risk and focuses on atelectasis, pneumonia, and respiratory failure. The target audience for this guideline is general internists or other clinicians involved in perioperative management of surgical patients. The target patient population is all adult persons undergoing noncardiothoracic surgery.