A 6 month old Turkish boy with the acrocallosal syndrome is reported. The patient, born to consanguineous, healthy parents, presented with macrocephaly, a prominent forehead, hypertelorism, polydactyly of the fingers and toes, severe motor and mental retardation, hypotonia, and absence of the corpus callosum. The mode of inheritance is discussed and our case is compared with previously reported cases of the syndrome.