Computed tomgraphy has been established as a useful imaging method in the diagnosis of tuberous sclerosis. By demonstrating the characteristic intracranial lesion it allows confirmation of the diagnosis and provides a noninvasive means of evaluating the patient with seizure and mental retardation. Authors analysed CT findings in 20 cases of tuberous sclerosis since March 1985 through August 1988. the results were as follows: 1) There are 14 men and 6 women with the age ragng from 6 months to 45 years. 2) Ventricular calcified tubers are noted at the frontal horn (16/20 80%) body (13/20, 65%) atrium (9/20, 45%) of the lateral ventricles 1 cases shows the hamartoma near the foramen of Monro. 3)In the cortical region 1 case of high density tuber and 2 cases of focal atrophy are noted. 4) In the white mater 3 cases of amorphous calcifications and 1 cases of demyelinating hypodensity are seen,