Aicardi's syndrome is a clinical entity characterized by agenesis of the corpus callosum, severe mental subnormality, seizures (most freque tly spasms in flexion), characteristic electroencephalographic changes (burst-supression pattern), typical chorioretinal lacunae, present only in females. Other associated findings are rib and vertebral dysplasias; frequently found are cortical heterotopias. This syndrome is of hereditary origin, now considered a probable X-linked dominant trait with male lethality. The authors describe two cases of this syndrome with the full clinical picture.