Lissencephaly has been long maintained a malformation involving only the brain. Classic lissencephaly includes agyria and pachygyria and it is the most severe form of malformations derived from abnormal neuronal migration. It is defined as a smooth or nearly smooth cerebral surface with absence of normal sulci and gyria. It encompasses a group of syndromes which show many different clinical conditions. Four groups are actually distinguished: classic lissencephaly variants, other lissencephalies including forms with unknown pathogenesis, microlissencephaly spectrum and Cobblestone cortical malformations. Several genes and proteins are involved in this syndromic spectrum and each year new molecular data are reported in the literature: classifications in this sense are always in progress. Lissencephaly now is recognised to involve not only the brain but also several other organs and districts including eyes, face, muscles, genital organs, heart and bones. Mental retardation and different form of epilepsies usually drug-resistant are the main clinical signs. The Authors in this topic discuss on this subject, underlying the different forms of lissencephaly their wide heterogeneity and the complex involvement of several organs.