A 3-month-old female baby was diagnosed as having Walker-Warburg syndrome (WWS), based on the following clinical findings: type II lissencephaly associated with marked ventricular dilatation, cerebellar malformation, retinal malformation, elevated serum creatine kinase level and abnormal muscle CT findings. She was a product of parents with consanguineous marriage. She presented with severe hypotonia and profound psychomotor retardation since birth. She developed infantile spasms at 8 months of age, and vitamin B6 was very effective. A genetic analysis revealed the absence of the founder haplotype commonly seen in Fukuyama-type congenital muscular dystrophy (FCMD), suggesting that the WWS gene is not always identical to the FCMD gene. When she was examined at the age of 4 years, she had no apparent further psychomotor development. Her clinical symptoms were more severe than those of the typical FCMD.