Two groups of 40 surgical Intensive Care Unit patients each, were included in the study. All patients had severe intraabdominal infections and sepsis, and septic score higher than 20. All were treated with individual specified conventional symptomatic therapy, and 40 of them received high doses of intravenous immunoglobulins. Significantly lower mortality rate was noticed in IVIG group (40%) than in control group (63.7%). Immunoglobulin therapy also decreased mortality rate in patients with septic shock, but it was no more effective than conventional therapy in patients with multiple organ failure (MOF).