We reviewed the records of 4778 infants who were admitted to the affiliated intensive care nurseries at the University of Washington in Seattle from Jan 1, 1980, through Dec 31, 1983. We evaluated the outcome for patients with bronchopulmonary dysplasia who required mechanical ventilation and supplemental oxygen for at least six months. Eight (53%) of 15 study patients were alive at 3 years of age. Preselected indexes measured during the first six months of life that were not associated with death before 3 years of age included growth measurements, fraction of inspired oxygen at 6 months of age, mean airway pressure, arterial partial pressure of carbon dioxide, and right ventricular hypertrophy. In contrast, recurrent cyanotic episodes requiring intermittent muscle paralysis or long-term sedation therapy to maintain gas exchange occurred in six of seven nonsurvivors and only one of eight survivors. The survivors have reactive airway disease and recurrent lower respiratory tract infections.