One hundred seventy-one patients admitted to a Medical ICU and who received treatment for respiratory failure with mechanical ventilation were studied for the development of pulmonary barotrauma (PBT) as manifested by pneumomediastinum, subcutaneous emphysema, or pneumothorax. Fourteen patients (8%; group A) developed this complication; they were younger, had higher maximal peak inspiratory airway pressures (PIP); and higher levels of maximal PEEP. We conclude that for medical patients treated for respiratory failure with mechanical ventilation, the incidence of PBT is 8% and that younger age, higher levels of PIP and PEEP seem to pose an increased risk for developing PBT.