Many prior studies involving a predominantly male population have demonstrated the importance of exercise test results in determining the outcome of patients with coronary artery disease. The prognostic significance of exercise testing in women is unknown. In our study, a total of 3,086 men and 747 women underwent maximal treadmill exercise testing, coronary angiography, and were prospectively followed for up to 16 years. They were divided into 3 groups (high, intermediate, and low risk) on the basis of exercise testing. Sixteen-year survival based on exercise test groups ranged from 38% to 61% in men and from 44% to 79% in women (p < 0.001). Among men, 12-year survival was enhanced by coronary artery bypass surgery versus medical therapy in the high-risk subgroup (69% vs 55%, respectively, p = 0.0025), but the 2 therapies were similar in the intermediate- and low-risk subgroups. Among women, neither medical nor surgical therapy resulted in improved 12-year survival rates in any of the 3 subgroups. These results suggest that exercise testing is helpful in assessing long-term survival in men and women. However, only exercise testing in men could identify a high-risk subset whose survival was enhanced by coronary artery bypass graft surgery.