PURPOSE: To investigate the clinical features of long-term follow-up, and the treatment responses in Korean children with Wilson disease(WD). METHODS: The clinical data from ninety-two children with WD, diagnosed at Seoul National University Hospital from 1976 to 1999, were reviewed. Mean duration of follow-up was 5+/-4.5 years. We analysed the patient's records based on the clinical manifestations, laboratory findings, and responses to the treatment. RESULTS: Age of initial presentation was 9.6+/-2.6 years. Mean age of patients who developed neurologic symptoms was 11.6 years. Initial manifestations were characterized as hepatic(70.6%), neurologic(6.5%), and both hepatic and neurologic(10.9%). Kayser-Fleischer(KF) rings were observed in 59 patients(64.1%). All neurologic patients had KF rings. Level of serum ceruloplasmin was low in 91 patients(98.9%). Multiple nodules in the liver and high signal intensity lesions in basal ganglia of the brain were observed on magnetic resonance imaging. Seventy-six patients(82.6%) showed favorable responses to penicillamine(PNC) and the rest of the patients with poor responses were treated with zinc sulfate, trientine, or liver transplantation. Neurologic symptoms improved with PNC in ten out of sixteen patients. However, despite PNC treatment, six patients deteriorated neurologically. Factors affecting the poor response to PNC were associated with the presence of fulminant hepatitis, hemolysis, and KF ring. Ten patients expired due to fulminant hepatitis(9), and hepatocellular carcinoma(1). Most of them died within five months after initial presentations. Ten-year survival rate was 85.4%. CONCLUSION: WD in children begins with various manifestations. PNC is an effective and safe drug to treat WD in most cases. However, the supplementary modalities such as zinc sulfate, trientine and liver transplantation should be considered when the patients show poor responses or adverse reactions to PNC.