Patients with metachromatic leukodystrophy (MLD) of juvenile or adult onset present with behavioral abnormalities. In nine patients, diagnosed between ages 11 and 33 years, behavior and neuropsychological test results disclosed a pattern of dementia combining features associated with both frontal and white matter abnormalities. All the patients had been considered to have a psychiatric disorder prior to the diagnosis of MLD, even though none had any of the cardinal features of schizophrenia or other major psychosis. Early diagnosis of late-onset MLD is important to provide access to appropriate effective therapy.