Perinatal and neonatal management of the very low birthweight infant has changed substantially in the 1990s. We analyzed the database records of 34,782 infants 501 to 1500 grams born from 1991 to 1995 and treated at the 157 neonatal units participating in the Vermont Oxford Network Database in an effort to identify trends in mortality, morbidity and care practices during the 5 year period. Infants, including those who were transferred, were followed for determination of survival status until they were discharged home. Mortality decreased from 17.9% in 1991 to 14.4% in 1995. Decreases were seen in all ethnic and racial groups. The proportion of infants who were inborn, who had prenatal care or who were delivered by c-section increased over time. Antenatal steroid exposure increased from 24% to 59%. Apgar scores increased and the rates of RDS and pneumothorax decreased. The proportion of infants treated with surfactant, nasal CPAP, HIFI ventilation and postnatal steroids increased, while the proportion who received any form of mechanical ventilation decreased. There was little change in the rates of necrotizing enterocolitis and intraventricular hemorrhage over the 5 years. Multivariable analyses showed that antenatal steroid exposure was associated with a significant decrease in mortality risk (odds ratio=0.59). The observed trends in mortality, morbidity and care practices were similar when the study sample was restricted to infants (n=16,096) at the 38 units participating in the database throughout the 5 years. We conclude that mortality rates for infants 501 to 1500 grams declined from 1991 to 1995. This decline can be largely explained by the increased use of antenatal steroids, but changes in other care practices may also play a role.[Supported by a grant from the Center for the Future of Children of the David and Lucile Packard Foundation.]