The authors present a patient with multiple sclerosis (MS) whose onset of illness was at 4 years of age. Three separate and distinct episodes of central nervous system (CNS) dysfunction associated with cerebrospinal fluid (CSF) pleocytosis, electroencephalographic (EEG) abnormalities, and extensive CNS white matter demyelination on both computerized tomography (CT) and magnetic resonance imaging (MRI) characterized her clinical course. Two episodes responded well to prednisone therapy.