A follow-up study was carried out on a cohort of 1142 very preterm (< 33 weeks) survivors who had ultrasound (US) brain scanning from birth. Follow-up was continued into adolescence, and included magnetic resonance imaging (MRI) of the brain at 14-15 y. Neonatal US findings and neurodevelopmental status at 1 y predicted outcome at 8 and 14 y, including cognitive development, poor interhemispheric interaction and school performance. MR brain imaging indicated that neonatal US accurately identified serious, permanent lesions in the brains of these very preterm infants, although US failed to recognise a large proportion of the abnormalities detected in adolescence by MRI. Atrophy of the corpus callosum was one of the commonest findings on MRI brain scans, supporting the hypothesis that damage to this important commissure may account for the poor school performance reported in very low birthweight infants.