The influence of ultraviolet autoblood irradiation (UV-ABI) on the treatment of patients with disseminated peritonitis has been studied. 109 UVABI procedures in 35 patients have been done. The general blood toxicity, plasma toxicity, sugar, creatinine and urea blood concentrations have decreased after the UVABI. Positive changes of immune system were detected: an increase of the T-lymphocytes number (60%), B-lymphocytes number (10%), and M.G.A immunoglobulins. The number of the circulating immunocomplexes has decreased by 36.5%. The UVABI is recommended for clinical use as an effective method of detoxication and immunocorrection.