Sixty-two consecutive septic surgical patients receiving standard multimodal intensive care unit treatment who developed a sepsis score of 20 or greater (day 0) were randomized to receive 0.4 g/kg of either intravenous IgG (29 patients) or human albumin (controls; 33 patients), repeated on days +1 and +5, in a prospective, double-blind, multicenter study. The two groups were similar in age, initial sepsis scores, and acute physiology and chronic health evaluation II score. A significantly lower mortality was recorded in the IgG-treated group (38%) than in controls (67%). Septic shock was the cause of death in 7% of IgG-treated patients and in 33% of controls. The results of this study indicate that high-dose IgG improves survival and decreases death from septic shock in surgical patients with a sepsis score of 20 or greater.