The relation between neuroradiological findings and upper limb function was examined in 53 children with hemiplegic cerebral palsy (CP). CT and MRI images of the children were classified into four groups (malformations, periventricular lesions, congenital cortical–subcortical lesions and postnatally acquired lesions). Additionally, each single affected neuroanatomical structure was noted. Clinical assessments included measures of activity (Melbourne Assessment of Unilateral Upper Limb Function and House Classification) and body functions (motor and sensory impairments). Comparative statistics and correlation analysis were used. Three children had a malformation, 28 a periventricular lesion, 14 a cortical–subcortical lesion and eight a postnatally acquired lesion. Children with periventricular lesions obtained the best motor functioning. Within this group, children with pure periventricular lesions performed significantly better compared to mixed lesions. The differences between congenital cortical–subcortical lesions and acquired lesions were not significant. Results further showed that middle cerebral artery infarctions and basal ganglia/thalamic lesions were significantly correlated to a worse performance. The type of lesion determined by the timing of the brain insult, and the location of the lesion distinguish children with hemiplegic CP regarding upper limb function. These insights are valuable for prognosis and may contribute to a better delineation of therapeutic interventions.