objective: to describe the incidence and main clinical characteristics of barotrauma during open lung ventilation (olv). design: a retrospective, observational, descriptive study was made of 100 patients with acute respiratory failure and bilateral pulmonary infiltrates. interventions: 1) a lung recruitment maneuver (lrm) with fixed ventilation pressure and progressive positive end-expiratory pressure (peep) elevations was carried out, followed by stepwise decreases until establishing open-lung peep at the value associated to maximum respiratory compliance; 2) assisted/controlled pressure ventilation to achieve a tidal volume of 6-8ml/kg; and 3) chest x-rays after lrm and daily for as long as respiratory failure persisted. results: nine patients, 7 with pneumonia and 2 with chest trauma, developed barotrauma (2 subcutaneous emphysemas and 7 cases of pneumothorax), representing an overall incidence of 9% and 16% in patients with primary lung injury. in 7 patients barotrauma was only a radiological finding; in the other 2 patients, it manifested as bilateral and tension pneumothorax, inducing pulmonary hypoventilation without hemodynamic impairment. only in these two cases was the ventilatory strategy modified. there were no differences in the airway pressures or volumes between patients with and without barotrauma. mortality was similar in both groups. conclusions: barotrauma was an exclusive complication of patients with primary lung injury, and the incidence in this group was high. in most cases, there were only radiological findings without clinical significance that did not require the suspension of olv. barotrauma was neither related to high pressures and volumes nor associated with increased mortality.