We report a case of multiple organ failure caused by the Bacillus cereus infection during acute lymphoblastic leukemia therapy, who was treated successfully. A 15-year-old male developed (B. cereus) sepsis on the 19th day after chemotherapy initiation. Polymyxin-direct hemoperfusion for septic shock was started, followed by continuous hemodiafiltration. His condition improved after starting the hemoperfusion. At the onset of sepsis, elevated levels of serum inflammatory cytokines, anti-inflammatory cytokines, and plasminogen-activator inhibitor complex-1 were observed. Serum levels of these cytokines and bioactive substances decreased after blood purification therapy, which correlated with the improvement of clinical symptoms.