PURPOSE: Bartter syndrome is a renal tubular defect in electrolyte transport characterized by hypokalemia, metabolic alkalosis and other clinical signs and symptoms. The aims of this study were to analyze the clinical manifestations and the short- and long-term outcomes of Bartter syndrome. METHODS: We retrospectively reviewed clinical history, laboratory finding of blood and urine, renal ultrasonography, and hearing tests of five patients who were diagnosed and managed with Bartter syndrome at Asan Medical Center from April 1992 to May 2007. We also evaluated height and body weight periodically after institution of therapy. RESULTS: All patients had poor oral intake, failure to thrive and polyuria. Three of them had maternal history of polyhydramnios and premature delivery. The mean age at diagnosis was 11.8 months. All children presented with hypokalemia, metabolic alkalosis, hyperreninemia. Their blood pressures were normal. One patient had nephrocalcinosis on renal ultrasonography and all of them had normal result in hearing tests. After treatment with indomethacin or other prostaglandin inhibitors and potassium supplementation, their clinical features improved with catch-up growth and improvement in the development during long-term follow-up. CONCLUSION: We emphasize that early diagnosis and proper treatment in patient with Bartter syndrome are related to better prognosis.