A novel approach to the treatment of surgical sepsis has been tried: cytokine-based immunotherapy. Human recombinant interleukin-2 (IL-2) and a mixture of native cytokines obtained by arteriovenous perfusion of xenospleen were used as a source of proinflammatory cytokines. Extracorporeal immunotherapy of 62 patients with surgical sepsis with mononuclear cells treated by autologous IL-2 resulted in a significant decrease of endotoxicosis and effective immunocorrection. Cytokine-based immunotherapy notably decreased the mortality of patients with generalized surgical infection--to 14.6%, which was lower than the expected mortality (35%) and the mortality in the control group (34.5%).