Abstract The antiangina effects of atenolol, 50 to 200 mg once daily, or nifedipine, 10 to 30 mg 3 times daily, were evaluated in a multicenter, randomized, double-blind, parallel study of 39 patients with known symptomatic coronary artery disease. Treatment was titrated to produce at least a 30% increase in treadmill exercise duration over placebo baseline and then maintained at that dosage for an additional 3 weeks. Both treatments produced significant (p < 0.001) increases in duration of exercise, total work and exercise capacity when compared with placebo baseline. These improvements in exercise performance were obtained with significant (p < 0.001) reductions in both ST-segment depression and rate-pressure product for atenolol compared with nifedipine. Furthermore, the total angina attack rate and rate at rest were significantly (p < 0.01) less frequent with atenolol than with nifedipine. Hence, the antiischemic effects of atenolol exceeded those of nifedipine, based on ST-segment depression and rate-pressure product at comparable workloads.