A review of 25,448 admissions was performed to evaluate the progress of neonatal intensive care at Weill Cornell Medical Center since 1978. Patients were identified by a review of admission and discharge data compiled by admitting staff. The following data were collected: birth weight, gestational age, place of birth (inborn versus outborn), discharge date, disposition. Length of stay was computed from these data. Data were organized according to year of admission. Admissions remained relatively constant with time. However the percentage of inborn infants steadily increased. Survival of the smallest infants (<600 g) remained poor, but overall survival of all infants improved over time. Length of stay for infants 1000 to 2000 g fell over time while that of other infants remained constant. These trends reflect changes in obstetric and neonatal practice over time, and include improved methods of antenatal care, neonatal pulmonary care, and nutrition, as well as changes in the distribution of neonatal and high-risk maternal care.