Bronchopulmonary dysplasia (BPD) is a significant cause of chronic pulmonary disease following mechanical ventilation of newborn infants. Although the exact pathogenesis of BPD has yet to be elucidated, high concentration of supplemental oxygen delivered by positive pressure through an endotracheal tube is thought to be a major predisposing factor. The only reported clinical trial of the administration of an exogenous antioxidant as vitamin E (20 mg/kg/day I.M.) to premature infants with respiratory distress syndrome who were receiving supplemental oxygen greater than 40% showed a shorter exposure to all levels of supplemental oxygen when compared to a control group. No roentgenographic changes of BPD were noted in any vitamin-E-treated infants. Vitamin E may modify the development of BPD, but until further clinical trials demonstrate a significant reduction in the incidence and severity of BPD, efforts should be made to minimize exposure to any of the associated factors in the pathogenesis of BPD.