Acute disseminated encephalomyelitis, an inflammatory and demyelinating disorder of central nervous system white matter, typically occurs following childhood viral infections. Although CT may demonstrate abnormalities, many children have normal CT studies in spite of widespread neurologic abnormalities. We report a series of five patients with the typical clinical presentation of disseminated encephalomyelitis who were studied using magnetic resonance imaging (MRI). In each case the children presented with progressive subacute neurologic abnormalities including headache, diplopia, ataxia, hemiparesis, seizures, dysarthria, and/or coma. CT was nondiagnostic. MRI clearly demonstrated multifocal white matter lesions of the cerebrum, brainstem, and cerebellum which corresponded to clinical signs. The patients improved dramatically with corticosteroid therapy. MRI showed progressive resolution of multifocal lesions in conjunction with clinical improvement.