A 21-month-old girl with cri-du-chat syndrome in conjunction with developmentaldelay underwent brain magnetic resonance imaging (MRI). The MRI showedhypoplasia of the brain stem, a normal cerebellum, thinning of the corpus callosum,and a lack of myelination in both anterior limbs of the internal capsule. She alsohad neonatal bilateral subependymal cysts. We believe that the symmetrical lack ofmyelination in both anterior limbs of the internal capsule could be a diagnostic clueof cri-du-chat syndrome.