Celiprolol is a cardioselective β‐adrenoceptor antagonist with attributed cardiostimulant properties. Its hemodynamic profile was compared in a dose‐response study with that of metoprolol, which is also cardioselective but lacks cardiostimulatory activity. In 24 patients with angiographically proved coronary artery disease, simultaneous hemodynamic and left ventricular ejection fraction (EF) values were determined at rest in the control (drug‐free) state and repeated 3 to 5 minutes after each of four intravenous boluses of Celiprolol, 1, 1, 2, and 4 mg, or equivalent β‐blocking doses of metoprolol, 1.25, 1.25, 2.5, and 5.0 mg. The effects of each drug on hemodynamics during exercise‐induced angina were determined by exercise testing in the control state and after the maximum cumulative dose of each drug. At rest, metoprolol reduced heart rate, cardiac index, and the left ventricular EF and increased pulmonary artery occluded pressure (PAOP), systemic vascular resistance, and left ventricular end‐systolic and end‐diastolic volumes. Celiprolol increased cardiac and stroke volume indices and the EF; the PAOP was reduced without change in other measured variables. During exercise, metoprolol significantly increased the PAOP, which was unchanged by Celiprolol. At exercise both drugs reduced cardiac index and heart rate, but neither altered the EF. The cardiac function curve demonstrated greater depression at rest after metoprolol than after Celiprolol; these differences were attenuated during dynamic exercise. The lesser adverse impact of Celiprolol on cardiac function may be attributable to ancillary cardiac stimulatory properties offsetting the cardiac depression after β‐adrenoceptor blockade.Clinical Pharmacology and Therapeutics(1986)39,5–14; do