The effects of glucocorticoids on fluid uptake and myocardial performance was investigated in 14 dogs and two baboons. The animals were placed into stimulated hemorrhagic shock using a servocontrolled pump to maintain arterial pressure at desired levels. Ventricular function curves were generated by stepwise changes in afterload or by venous infusion and the resultant data were grouped by digital computer into similar preload, heart rate, and afterload groupings. Fluid uptake was monitored from the pump reservoir. Methylprednisolone was given intravenously, 30 mg/kg, approximately 3 hr after the postinfusion period. Fluid loss decreased and ventricular performance improved, as measured by maximal dp/dt, (maximal dp/dt)/developed pressure, and time to peak ventricular pressure. The improvements with steroid infusion were relatively small, however, and were not maintained for more than about 3 hr. Heart rate decreased markedly in response to the steroid, despite a general vasodilator response. The glucocorticoids appear to have mild beneficial effects on the myocardium and on capillary permeability in the presence of high circulating levels of catecholamines in the postinfusion phase of hemorrhagic shock.