During a period from December 1976 to December 1980 a total of 233 epileptic patients underwent brain CT at the Department of Neuropsychiatry, Yamaguchi University Hospital, with 108 (46.4%) of these 233 having been found to have abnormal findings. No more than 6.3% of patients with primary generalized epilepsy had an abnormal brain CT. In contrast, approximately a half of patients with each of the other types of epilepsy showed abnormalities on brain CT: secondary generalized epilepsy, 50.0%