The hemodynamic effect of dobutamine infusion (DI) was studied in 19 patients with septic shock. DI resulted in hemodynamic improvement as indicated by a significant increase in cardiac index (+36%,p< 0.001), stroke index (+15%,p< 0.01), mean arterial pressure (+20%,p< 0.01), and a significant decrease in avDo2(-27%,p< 0.01). This hemodynamic improvement occurred concomitantly with a fall in both right and left filling pressures. Mean systemic arterial resistance remained unchanged with a scatter of individual responses depending on other factors, such as infusion rate, initial vascular resistance, and underlying hemodynamic setting.In patients mechanically ventilated, venous admixture in the lung (Qs/Qt) during DI increased significantly (+30%,p< 0.001) and insignificantly reduced Pao2, but this adverse effect was not observed when PEEP was used in patients mechanically ventilated.It is concluded that dobutamine can be useful in management of septic shock, particularly when filling pressures are high because of fluid overload or cardiac failure.