We have analyzed the MRI findings from the brains of 33 children with congenital hemiplegia. Referral of these children to our hospital was either because of neurological problems or a history of complicated birth. According to maturation-dependent pathophysiological mechanisms we have classified the lesions into the following five groups: 1. malformations/prenatal encephalo-clastic lesions, 2. periventricular leukomalacia or atrophy, 3. diencephalic lesions, 4. subcortical and cortical lesions, and 5. normal findings. Combination of lesions was not uncommon. The neuroradiologically most prominent and most expanded lesions determined the classification to the different groups. We detected malformations/encephalo-clastic lesions (Group 1) in 5 children; one of these children also presented additional lesions of Groups 2 and 3. Six children displayed periventricular leukomalacia (Group 2), and in one child in combination with diencephalic and subcortical lesions. Ten children exhibited diencephalic lesions (Group 3), in one case combined with periventricular leukomalacia. The MRI of seven children showed subcortical/cortical lesions (Group 4), in four cases extending into diencephalic structures. Two children had a combination of evenly matched periventricular, diencephalic and subcortical/cortical lesions, where it was impossible to define a principal lesion. Three children had normal MRI findings. Significantly, 8 of 33 children had bilateral lesions although presenting with hemiplegia. The large proportion of diencephalic lesions, not described in similar CT studies, and the small number of normal MRI findings show the value of MRI in evaluation of congenital hemiplegia. The ability to correlate, to some extent, neuroradiological findings of damage to developmental stage affords the conclusion that at least a third of the children in our series with congenital hemiplegia suffered prenatal damage.