An 8 year-old boy was presented with typical symptoms of neuromyelitis optica. Hematologic data revealed leucocytosis and elevated erythrocyte sedimentation rate(ESR). CSF analysis showed elevated protein and lymphocyte dominant leucocytosis. Treatment with high dose steroid was administered. He recovered fully within a few weeks after the onset or paraparesis. Neuromyelitis optica is a clinical syndrome. Pathophysiologically, it is a autoimmune process involving the optic nerve and the spinal cord. It is characterized by rapid progressive paraparesis and bilateral visual disturbance. There are no definitive laboratory clues for diagnosis. Treatments including the use of steroid, ACTH, antiviral agent and immunosuppresant, all result in variable effect. Prognosis is very variable ranging from full recovery to death. The most common cause of death is respiratory failure with the cord lesions. Neuromyelitis optica is very rare in Korea. We report the case with review of the literature.