OBJECTIVES: To determine if the incidence of sonographically detected cystic periventricular leukomalacia (PVL) and periventricular hemorrhagic infarction (PVHI) have changed over the past decade and to determine if a decline in cystic PVL was associated with a change in neurodevelopmental outcome. STUDY DESIGN: Premature newborn infants admitted to our intensive care nursery from 1992 to 2002 were identified in a comprehensive nursery database. Premature newborn infants had routine neurosonography by means of a standardized protocol. Infants weighing ≤1500 g at birth surviving to nursery discharge were enrolled in a nursery follow-up clinic. RESULTS: Adjusting for gestational age, there was a significant decrease in cystic PVL from 1992 to 2002 (P = .003) without a concurrent decrease in PVHI (P = 0.5). Cystic PVL and PVHI accounted for only 9 of the 28 cases of cerebral palsy and 12 of 90 cases of abnormal Developmental Scores in infants weighing <1500 g at birth. The decline in cystic PVL was not associated with improved developmental outcome from 1992 to 2002. CONCLUSIONS: The incidence of cystic PVL declined significantly from 1992 to 2002 at our center. Cystic PVL was detected by ultrasound in a minority of infants with abnormal neurodevelopmental outcome, indicating that other forms of cerebral injury account for the majority of abnormal neurodevelopmental outcomes in premature newborn infants.