The study investigated the acute hemodynamic changes induced in patients with angiographically confirmed coronary artery disease by 3 beta-blockers: metoprolol, cardioselective without intrinsic sympathomimetic activity (ISA), group I, 11 patients; bunitrolol, noncardioselective with ISA, group II, 11 patients; oxprenolol, noncardioselective with ISA, group III, 11 patients. Hemodynamic variables were obtained at rest and during exercise, before and 45 min after 10 mg i.v. of the drug. Changes in LVEDP and cardiac indexes were such as LV function was improved in 1 patient of group I, 7 patients of group II and 5 patients of group III; impaired in 4 patients of group I and in 1 patient of group III; unchanged in the others. Contractility indexes were less influenced by bunitrolol and oxprenolol. During exercise there was a significant difference between groups for LVEDP which was lower in group II (P less than 0.01). The data seem to indicate that the choice of the beta-blocker may be of importance when it is desirable that an already compromised cardiac function be not further impaired by pharmacological intervention.