A total of 197 consecutive patients undergoing pneumonectomy at the M.D. Anderson Cancer Center from 1982 to 1987 were reviewed. Sixty-five variables were analyzed for the predictive value for perioperative risk. The operative mortality rate was 7% (14/197). Patients having a right pneumonectomy (n = 95) had a higher operative mortality rate (12%) than patients having a left pneumonectomy (1%, p less than 0.05). The extent of resection correlated with the operative mortality rate (chest wall resection or extrapleural pneumonectomy, n = 39, 15%; versus simple or intrapericardial pneumonectomy, n = 158, 5%; p less than 0.05). Patients whose predicted postoperative pulmonary function, by spirometry and xenon 133 regional pulmonary function studies, was a forced expiratory volume in 1 second greater than 1.65 L, forced expiratory volume in 1 second greater than 58% of the preoperative value, forced vital capacity greater than 2.5 L, or forced vital capacity greater than 60% of the preoperative value had a lower operative mortality rate (p less than 0.05). Atrial arrhythmia was the most common postoperative complication (23%). Xenon 133 regional pulmonary function studies are useful in predicting the risks of pneumonectomy.