This report describes the neonatal outcomes of 1765 very low birth weight (less than 1500 g) infants delivered from November 1987 through October 1988 at the seven participating centers of the National Institute of Child Health and Human Development Neonatal Intensive Care Network. Survival was 34% at less than 751 g birth weight (range between centers 20% to 55%), 66% at 751 through 1000 g (range 42% to 75%), 87% at 1001 through 1250 g (range 84% to 91%), and 93% at 1251 through 1500 g (range 89% to 98%). By obstetric measures of gestation, survival was 23% at 23 weeks (range 0% to 33%), 34% at 24 weeks (range 10% to 57%), and 54% at 25 weeks (range 30% to 72%). Neonatal morbidity included respiratory distress (67%), symptomatic patent ductus arteriosus (25%), necrotizing enterocolitis (6%), septicemia (17%), meningitis (2%), urinary tract infection (4%), and intraventricular hemorrhage (45%, 18% grade III and IV). Morbidity increased with decreasing birth weight. Oxygen was administered for greater than or equal to 28 days to 79% of less than 751-g birth weight infants (range between centers 67% to 100%), 45% of 751- through 1000-g infants (range 20% to 68%), and 13% of 1001- through 1500-g infants (range 5% to 23%). Ventilator support for greater than or equal to 28 days was given to 68% of infants at less than 751 g, 29% at 751 through 1000 g, and 4% at greater than 1000 g. Hospital stay was 59 days for survivors vs 15 days for infants who died. Sixty-nine percent of survivors had subnormal (less than 10th percentile) weight at discharge. The data demonstrate important intercenter variation of current neonatal outcomes, as well as differences in philosophy of care and definition and prevalence of morbidity.