Twenty-three infants with an infarct in the territory of the middle cerebral artery are reported. The diagnosis was made using cranial ultrasound in all, confirmed on postmortem in two cases and on MRI, performed during the neonatal period or in infancy, in 18 of the 20 survivors. Involvement of the main branch was present in 7 cases and three of these had a gestational age of less than 35 weeks. In the other 16 infants, involvement of a cortical branch or one or more of the lenticulostriate branches was present and all but three of these had a gestational age of 34 weeks or less. While involvement of the main branch was usually diagnosed on postnatal day 1 or 2 using ultrasound, involvement of the lenticulostriate branches was noted as a wedgeshaped echogenic lesion in the caudate nucleus, thalamus or putamen, between day 4 up till day 24, and at term age in one of the cases. Neurodevelopmental outcome of those with involvement of the main branch was disappointing as all survivors developed a hemiplegia, associated with epilepsy in two; while so far only three of the other 16 infants developed cerebral palsy, one a hemiplegia and one athetoid cerebral palsy. Global delay was present in a further three cases. Infarcts in the region of the middle cerebral artery can occur in both preterm as well as fullterm infants. Involvement of the main branch also occurred in infants with a gestational age below 35 weeks and resulted in the development of a hemiplegia in all survivors. Involvement of one of the other branches was especially common in preterm infants, who had a more favourable outcome. As the lesion in the latter group was usually not present before the end of the first week, serial ultrasound up till term age is needed in order to identify these lesions.