Ten children (age 2 months to 8 years) with a congenital cytomegalovirus (CMV) infection were studied by magnetic resonance imaging (MRI) using a 2.35 Tesla magnet. CMV infection was confirmed by serological investigations and virus culture in the neonatal period. Nine children had severe mental retardation and cerebral palsy, 1 patient suffered from microcephaly, ataxia and deafness. The cranial MRI examination showed the following abnormalities (N): dilated lateral ventricles (10) and subarachnoid space (8), oligo/pachygyria (8), delayed/pathological myelination (7), paraventricular cysts (6), intracerebral calcification (1). This lack of sensitivity for calcification is explainable by the basic principles of MRI. The paraventricular cystic lesions were adjacent to the occipital horns of the lateral ventricles and separated only by a thin membrane. This finding might represent a "new sign" for congenital CMV infection in MRI examinations, being characteristic but nevertheless nonspecific, like calcification in CT.