Authors describe twelve children with diagnosis of tuberous sclerosis (TS) within the first year. All children had seizures, being infantile spasms in 7 cases (58%). All but one showed severe mental retardation. Hypopigmented patches in 2 (16.6%) and retinal phakoma in one case (8.3%). Skull Rx were normal in all cases, while the CT showed early intracranial calcifications in the 100% of the patients and areas of hypodensity in the 50%. The CT is the most useful test for the early diagnosis of TS when the clinical diagnosis has not been firmly established.