Calcium antagonists and beta blockers may retard or inhibit atherogenesis. This study investigated whether nifedipine or propranolol influences coronary atherosclerosis in humans. In selected patients with effort angina and proven coronary artery disease, the cineangiographic pattern after 2-year therapy with nifedipine (group 1, 39 patients), propranolol (group 2, 36 patients) or isosorbide dinitrate (group 3, 38 patients) was compared to that before treatment. The disease evolved to a different extent in the 3 groups. Patients with evidence of progression of old narrowings and appearance of new narrowings were significantly fewer in group 1 (31% and 10%) than in group 2 (53% and 34%) and group 3 (47% and 29%). The number of stenoses with evidence of progression was significantly smaller after nifedipine (14), and larger after propranolol (39) compared with group 3 (24). Thus, nifedipine seemed more protective than the other 2 drugs against coronary atherosclerosis. The coronary risk factors were normal in the nifedipine group and remained so with treatment, suggesting that they were dissociated from influences on atherosclerosis. The evolution, as judged by the number of narrowings with progression, appeared significantly (p less than 0.01) worse with propranolol than with isosorbide dinitrate. Propranolol caused unfavorable modifications of serum lipids; there was a 28% increase in total triglycerides and a 25% decrease in high density lipoprotein cholesterol at 12 months in group 2.