The effects of the prone position on the improvement of oxygenation in patients with ARDS were reported already twenty years ago. Recent studies have shown that the prone position would improve the ventilation and perfusion relationship as it improves the ventilation in the local area without altering the pulmonary blood flow during the support of ventilation in the patients with ARDS, We have applied the prone position repeatly on the patient with ARDS which developed after the removal of a bilateral pulmonary empyema and decortication, The initial effect of the prone position on oxygenation improved the PaO2/FiO2 (arterial oxygen tension divided by inspired oxygen concentration) ratio, 104.3 to 132.9, at FiO2 0.7. Improvement of oxygenation was maintained with repeat position change, three times over 24 hours, from supine to prone position.