The aim of this study was to validate the accuracy of real-time ultrasound (US) in the diagnosis of periventricular leukomalacia (PVL). US changes of PVL were correlated with autopsy results. During a 12-month period, all premature infants of 34 weeks' gestation or less (group A) and all neonates of more than 34 weeks' gestation who presented with abnormal neurological signs (group B) were studied with an ATL mechanical sector scanner (5 and 7.5 MHz). The overall incidence of PVL was 13.3%. In group A (n = 83), 13 infants had PVL and 3 died. In group B (n = 36), three developed PVL and two died. Autopsy was performed in the five infants. US revealed the sequence of lesion: - the early stage with increased echogenicity in the periventricular white matter, - the late stage with area of reduced echogenicity appearing in the most echogenic zone and resulting in cystic cavitation. Autopsy confirmed PVL lesions in all five infants. The increased echogenicity corresponded to necrosis with either vascular congestion and/or secondary bleeding, the reduced echogenicity to cystic degeneration with gliosis. US scan be used for the detection of PVL.