Endotoxin-removal direct hemoperfusion column containing polymyxin B immobilized fibers (PMX-DHP) is an effective procedure for the treatment of sepsis-induced acute respiratory distress syndrome (ARDS). We investigated retrospectively the effects and appropriate timing of PMX-DHP induction for directly induced ARDS in 38 patients. PMX-DHP was carried out twice for two hours. Blood pressure, heart rate (HR) and PaO(2)/FIO(2) (PF) ratio, leukocytes, platelets, endotoxin, inflammatory cytokines and clusters of differentiated peripheral neutrophils and monocytes were measured before and after PMX-DHP. Acute Physiology and Chronic Health Evaluation (APACHE) II scores, Sequential Organ Failure Assessment (SOFA) scores and lung injury scores (LIS) were determined at the time of starting PMX-DHP. The underlying causes of ARDS were pneumonia in 29 patients and aspiration pneumonia in 9 patients. The patients were divided into Survivors (n = 21) and Nonsurvivors (n = 17). Mortality was 45% at 30 days after PMX-DHP. The APACHE II and SOFA scores and the LIS were not significantly different between the two groups. The time from the onset of ARDS to the start of PMX-DHP was significantly delayed between the two groups. PMX-DHP significantly improved the PF ratio, HR and systolic blood pressure in the Survivors compared to the Nonsurvivors. The function of active monocytes in the peripheral blood was significantly suppressed after PMX-DHP. This early induction of PMX-DHP is indicated for directly induced ARDS. In the Nonsurvivors, this delay could have led to undesirable responses to oxygenation and circulation after PMX-DHP.