Miller-Dieker syndrome is a contiguous gene deletion syndrome involving chromosome 17p13.3, which is characterized by type 1(classical) lissencephaly and typical craniofacial abnormalities. Children with Miller-Dieker syndrome have profound psychomotor retardation, seizures that often are intractable, chronic feeding problems that lead to recurrent pneumonia, and shortened lifespan. We have experienced a Miller-Dieker syndrome female who has lived to 8years, showing severe mental and motor retardation and intractable epilepsy. She was diagnosed as Miller-Dieker syndrome in the neonatal period, showing typical facial features, type 1 lissencephaly, and chromosome 17p13.3 microdeletion in fluorescence in situ hybridization. Infantile spasm occurred at 4 months of age and progressed to Lennox-Gastaut syndrome at 3 years and 6 months, both of which were not controlled by antiepileptic drugs.