Several randomized clinical trials have shown that surfactant therapy improves the pulmonary status of infants with respiratory distress syndrome and has the potential to reduce morbidity and mortality in these infants. Relatively little is known, however, about the long-term consequences of surfactant treatment. In this report, the results of health and developmental assessment are described at 1 and 2 years of age of 32 survivors of an initial group of 41 infants enrolled in a randomized clinical trial of bovine surfactant therapy. The frequencies of abnormal findings were comparable in the two groups although there was a trend toward a greater frequency of allergic manifestations in the control group (6 of 16 (38%) vs 1 of 15 (7%), P = .08). Similarly, no differences were seen in the mental and motor scores of the Bayley Scales of Infant Development at either 1 or 2 years of age. This study and other recently published reports of follow-up studies of infants treated with surfactant provide encouraging evidence that major long-term side effects do not result from surfactant therapy.