In patients with respiratory pathology changes in respiratory physiology may lead to clinical problems during the conduct of anesthesia and the perioperative period. An understanding of the disease processes that can affect the lungs and pleura allows the anesthesiologist to account for the potential complications of these conditions and manage the anesthetic accordingly. This article describes the initial evaluation of a patient with respiratory problems. A thorough medical history, physical examination and some functional tests are the keys in decision-making in preparation for anesthesia and surgery. The burden of respiratory disease is reviewed, and some important areas of current interest are highlighted.