Four children characterised by megalencephaly and cerebral leukoencephalopathy with infantile onset, defined on the basis of clinical and neuroimaging findings are reported. The course of the disease is characterised by stabilization of the macrocephaly and slow clinical deterioration. The CT scan findings include supratentorial diffuse hypodensities in the white matter and swelling. The characteristic MRI findings include the discrepant severity in comparison with the clinical picture, diffuse supratentorial white matter abnormalities with subcortical cysts. The basic defect of the disease is unknown. Considering the high rate of consanguinity among the parents and the presence of two affected sibs in one family, an autosomal recessive inheritance is assumed. We report four unrelated cases of this entity.