PURPOSE: Acute disseminated encephalomyelitis(ADEM) is an immunologically mediated demyelinating disease of the central nervous system. We investigated the clinical features and outcomes of children with ADEM presenting with different neurologic symptoms and clinical courses. METHODS: Fifteen cases(male 10 and female 5) of ADEM who were diagnosed in the department of pediatrics, Samsung Medical Center from July 1997 to April 2001 were reviewed. RESULTS: The ages at initial presentations were from 1 year 5 months to 14 year 8 months. The presence of preceding events was present in all patients. The most common presenting symptom was seizure(60%), followed by altered consciousness(40%), ataxia(33 %), cranial nerve palsy, headache, quadriparesis, visual disturbance, and tremor. Brain magnetic resonance imaging showed relatively symmetrical, multifocal hyperintense lesions on T2-weighted image. One out of 4 brain CT showed an abnormal finding and remaining 3 cases showed abnormal findings in MRI only. Two patients had normal MRI findings at the initial phase of the illness but later revealed MRI findings compatible with ADEM. Thirteen patients were managed on high dose methylprednisolone therapy and/or intravenous immunoglobulin. After treatments, all patients revealed rapid clinical recovery. Relapse occurred in four patients(26%) 3 weeks to 1 year 6 months after developing their first illness. Among them, two patients were diagnosed as multiple sclerosis later. CONCLUSION: We experienced 15 children with the initial diagnosis of ADEM. Even though immunosuppressive drugs were effective to eliminate their presenting symptoms in most patients, there was 26% of relapse rate with 2 patients with later diagnosis of multiple sclerosis during long-term follow-up suggesting heterogeneity existed with regard to etiology and clinical courses of ADEM.