Simple pulmonary function studies can be utilized successfully for diagnosis of pulmonary problems in surgery patients preoperatively. In the present study, randomly selected "poor risk" patients were treated preoperatively and postoperatively with cessation of smoking, bronchodilator drugs, antibiotics, inhalation of humidified gases, segmental postural drainage, and chest physiotherapy. When compared to nontreated poor risk patients, the treated patients had a marked reduction in postoperative morbidity and mortality due to pulmonary complications. Although the frequency and the severity of pulmonary complications were somewhat greater in the treated patients than in a group of "good risk" patients who were considerably younger in age, the differences were not significant. Extension of these simple therapeutic measures to large numbers of poor risk patients should reduce postoperative morbidity and mortality, allow earlier discharge, and lower the costs of patient care.