Magnetic resonance imaging (MRI) was performed in 33 children using a 2,35 T MR system. The intention was to determine the various types of morphological abnormalities seen in primary microcephaly and the frequency with which they occur. MRI findings were typical for cytomegalovirus infection in six patients. Cerebral malformations were found in 14 cases and patchy white matter lesions in both hemispheres in two subjects. MRI appeared to be abnormal in eight of the remaining 11 children. However, we were unable to provide an exact interpretation of the findings. All the children with MRI abnormalities with the exception of two were neurodevelopmentally deviant. Thus, MRI revealed abnormalities in the majority of infants with primary microcephaly and neurodevelopmental disturbances. It appears to be more sensitive than cranial ultrasound and computed tomography.