We report our experience with the use of enoximone in 5 patients with severely depressed preoperative myocardial function who underwent cardiac surgery. In patients 1 and 2, enoximone was administered as the inotropic of choice before cardiopulmonary bypass (CPB) and a substantial improvement of cardiac index was achieved; in these patients, enoximone administration after CPB permitted to overcome low cardiac output which persisted after high dose dobutamine in patient 1, and in patient 2 right ventricular contractility improved. In patient 3 the use of enoximone permitted the discontinuation of CPB, which had not been previously possible with the association of dopamine and dobutamine. In this patient, adrenaline perfusion improved the low cardiac output syndrome but resulted in poorly tolerated side effects. However, in patient 4 the administration of enoximone during pre-CPB did not improve in a reduction in filling pressures without an increase in the cardiac index because the patient was hypovolemic. In patient 5, the administration of enoximone permitted to interrupt the infusion of dobutamine and to reduce the dose of sodium nitroprusside, which had resulted in significant tachycardia, with increased myocardial contractility and a reduction of vascular peripheral and pulmonary resistances. We conclude that enoximone, single or in association with other inotropics, should be considered a drug of choice in patients undergoing cardiac surgery who develop a low cardiac output syndrome.