THERE HAS been a tendency to equate shock, regardless of its origin, with a low cardiac output and high total peripheral resistance. While our experience suggests that this is true of hypovolemic and cardiac shock, the same cannot be said of the septic form. In studies performed in the shock unit of the Detroit Receiving Hospital it was found that septic shock was generally characterized by low total peripheral resistance and a cardiac output which was often normal or raised. It is the purpose of this present study to present the clinical and hemodynamic picture of septic shock. Methods and Materials Hemodynamic Measurements. —Systemic blood pressure was obtained by cannulation of the radial or femoral arteries. Central venous pressure was measured through a catheter inserted into the brachial or basilic vein and advanced centrally into the thorax until brisk excursion with respiration was evident. Intravascular pressures were measured with a