A large number of terms has been applied to this clinical and pathophysiologic complex, all of which are encompassed by the designation ARDS. The use of this term,however, should not obscure the fact that the initial insults and mechanisms of lung injury vary and that therapy should be directed not only toward the secondary alterations in pulmonary function but toward the initiating event or events as well. In therapy, the use of continuous positive-pressure ventilaion(CPPV) incorporating PEEP has a well-documented role in the management of patients with ARDS. The veneficial effect of this pattern of ventilation is mainly attributable to the increase in FRC that it produces. As previously discussed, several factors combine to reduce lung volumes in patients with ARDS. Positive end-expiratory pressure overcomes threade by producing a constantly positive distending pressure across the walls of airways and alveoli; this reestablishes their patency and increases FRC. We report a case of ARDS after operation for Vesico-cervical fistula developed in a 34 years old woman and the relevant literature has been reviewed.