We describe the CT and MR findings in molybdenum-cofactor deficiency, a rare metabolic disorder which is caused by the defect of a molybdenum-containing enzyme cofactor. The CT (3 patients) and/or MR studies (3 patients) of 4 children, which became symptomatic with intractable seizures within the first days after birth and finally turned out to have molybdenum cofactor deficiency, were reviewed. All patients showed multicystic leukencephalopathy and a normal newborn pattern of myelination of the brainstem. A striking finding in some studies was an abnormal shape of the frontal horns of the dilated ventricles caused by severe volume loss of the basal ganglia, especially of the caudate nucleus, and of the corpus callosum. MRI was superior to CT in the demonstration of these lesions. In molybdenum-cofactor deficiency, which can be diagnosed by a typical laboratory pattern, CT and MR show the findings of severe perinatal brain damage. The abnormal shape of the frontal horns, although possibly not specific, may even suggest molybdenum-cofactor deficiency in newborns with intractable seizures.