Computerized transverse axial tomography (CTAT) of the brain has been used routinely, as well as the EEG, to study patients with epilepsy. In patients with the various electro-clinical types of epilepsy -- primary, secondary, and partial -- it gave accurate information about the frequency, topography, and severity of morphological abnormalities. In the various types of organic lesion -- tumor, posttraumatic, postischemic, postinfectious, etc. -- it markedly increased the ability to establish etiology. Especially notable was the finding of (1) tumor in 16% of patients over 20 years of age, and (2) the determination of a type of pathology that has received little attention -- postischemic occipital porencephaly probably due to occlusion of the posterior cerebral artery, either at birth or in early infancy.