Cerebral computerized tomography (CT) was obtained in 37 children with congenital hemiparesis to document the type of cerebral anomalies found in this group, correlate them with various features of the neurological handicap and clinical history and determine the prognostic and practical value of this examination in a newly diagnosed case. The CT-findings were: 1. normal CT: 4 children (11%); 2. unilateral ventricular enlargement: 9 children (24%); 3. others (cortical and subcortical lesions): 24 children (63%). In this latter group, special patterns were found: a) focal ischemic lesions: 7 cases; b) cystic porencephaly: 2 cases; c) ventricular deformities with hydrocephalus: 7 cases; d) varia: 8 cases. The children with normal CT or unilateral ventricular enlargement had mild or moderate hemiparesis without epilepsy or mental retardation. The third group comprised the more severe cases but the prognosis was very variable. The different types of CT-lesions, their possible origin and neuropathological correlates are described and compared with two previous studies. The variety of lesions found in this series and the relative prognostic value of the CT-Scan justify this examination in a newly diagnosed case.