For the treatment of multiple organ failure (MOF) through sepsis, we have commonly applied various blood purification modalities during the perioperative period. From January 1996 to December 2000, 33 patients with MOF through sepsis were admitted and operated on in the First Department of Surgery, Akita University School of Medicine, and 21 of these 33 patients were treated using various blood purification modalities during the perioperative period: endotoxin-adsorbing therapy using polymyxin B (PMX) in 17 patients, continuous hemofiltration (CHF)/continuous hemodiafiltration (CHDF) in 15 patients, and plasma exchange (PE) and CHDF in 3 patients. Of the outcome of these 33 patients with MOF through sepsis, 17 survived and 16 died (48% mortality). Of the 21 patients with MOF through sepsis treated by surgery and blood purification, 12 survived and 9 died (43% mortality). We evaluated APACHE II and the number of failed organs before operation. Amongst the group with 12 survivors and 9 deaths, Acute Physiology and Chronic Health Evaluation II (APACHE II) was 15 ± 5, 23 ± 2 and the number of failed organs was 2.7 ± 0.7, 3.9 ± 0.8, respectively. An increased APACHE II score and number of failed organs were significantly associated with mortality. As to the treatment of MOF through sepsis due to acute peritonitis, patients with APACHE II scores ranging from 15 to 20, and those with 2–3 failed organs seem to be the candidates for the application of blood purification during the perioperative period.