The hemodynamic effects of cardiac glycosides were studied in 13 patients with cardiogenic shock. Intravenous administration of ouabain, deslanoside, or digoxin produced a prompt pressor effect which was characterized by increases in systemic vascular resistance and tension time index and no change or increase in right atrial pressure (RAP) and left ventricular enddiastolic pressure (LVEDP). Acute pulmonary edema developed during this period in one patient. During the later phase, 15 to 60 minutes after infusion of digitalis, there were increases in the maximum rate of rise of left ventricular pressure (LV dp dt), mean systolic ejection rate, and left ventricular stroke work usually with a fall in RAP or LVEDP. Despite the evidence of improved myocardial function, cardiac output (CO) was not significantly increased and was always lower than that attained during infusion of isoproterenol. It is concluded that digitalis is not very effective by itself in restoring blood flow in cardiogenic shock and that the early peripheral vasoconstrictor effect following intravenous administration may be deleterious in some patients.