Patients with malformations of cortical development (MCD) present with a wide spectrum of clinical manifestations ranging from asymptomatic cases to those with epilepsy and developmental problems. Clinical presentation of MCD is variable and depends on the affected cortical area. While severe malformations can be recognized with definite developmental retardation and early-onset recurrent seizures, mild malformations are usually identified at any age, mostly during evaluation following a seizure. With the help of high resolution neuroradiological imaging techniques, there has been an increase in the number of cortical developmental lesions. The etiology in many MCDs is unknown. It is possibly a general response of the developing brain to genetic and environmental factors. Alterations during neuronal proliferation, migration and organization stages of the developing brain constitute the basis of these malformations. During the developmental stages, intervening genetic and prenatal environmental factors may contribute to the development of malformations. Nevertheless, in the majority of cases the cause is unknown. Anahtar Kelimeler : kortikal gelişimsel malformasyonlar, klinik, etiyoloji, genetik, malformations of cortical development, clinical course, etiology, genetic