Eighteen patients with chronic, stable angina were studied in a double-blind, placebo-controlled, 3-way, crossover study in which they received 4 weeks of treatment with a once-daily dose of bepridil, 300 mg, a once-daily dose of long-acting propranolol, 160 mg, and placebo. Heart rate at rest during bepridil treatment was less than that during placebo (p less than 0.01), whereas propranolol reduced heart rate compared with placebo (p less than 0.001) and bepridil (p less than 0.01). Systolic blood pressure at rest did not change during the 3 treatment phases. Exercise time to onset of angina and to development of moderate angina were reproducible over the 24-hour period during each treatment phase. Treadmill walking time to onset of angina and to development of moderate angina was significantly prolonged during bepridil (p less than 0.01) and during propranolol treatment (p less than 0.05). Heart rate at peak exercise was similar during bepridil and during placebo, but was markedly reduced with propranolol treatment (p less than 0.001). Systolic blood pressure during exercise was similar during placebo and bepridil, but was substantially lower during propranolol treatment (p less than 0.01).