Background: Lissencephaly is a brain malformation caused by defective neuronal migration and characterized by epilepsy and severe psychomotor retardation, with high mortality. Objective: Describe the clinical presentation, neuroradiologic characteristics and evolution of 9 children with lissencephaly. Results: 9 children (4 males) were controlled between 1999 and 2007. The diagnosis was made during the neonatal period in 4 patients; 3 cases presented seizures and microcephaly, while 1 newborn had a prenatal ultrasonography showing cerebral malformation. The diagnosis was made during the first year of life in 5 patients; 4 cases had epilepsy, severe psychomotor retardation and microcephaly, while 1 child had macrocephaly. During follow-up period, 8/9 children had catastrophic epilepsy and severe psychomotor retardation. Conclusions: Lissencephaly is a pathology with bad prognosis, usually diagnosed during the first year of life. Symptoms include refractory epilepsy and severe psychomotor delay. It is important to complete the evaluation with genetic studies and high - resolution neuroimaging, in order to perform an early diagnosis, predict evolution and offer genetic counsil