To evaluate three types of exercise testing in prediction of death or prolonged mechanical ventilation after lung resection in high-risk patients, 16 patients underwent evaluation prior to resection. Eleven patients (group 1) had minor or no complications (arrhythmia, atelectasis, pneumonia) and five patients (group 2) died within 90 days of surgery. Exercise testing showed that group 1 had a longer 6-min walk distance and a higher stair climb than group 2. The maximum oxygen uptake on a cycle ergometer was not significantly different between groups, although only ten patients completed this test. Group 1 had a significantly greater calculated oxygen uptake with stair climbing than group 2. A 6-min walk distance of greater than 1,000 feet and a stair climb of greater than 44 steps were predictive of successful surgical outcome. Preoperative exercise testing is a useful adjunct to traditional spirometric testing in evaluation of the high-risk surgical patients.