Background : Cardiomyopathy and ventricular arrhythmias are leading cause of morbidity and mortality in the patients with end-stage renal disease. Methods : Retrospective and prospective investigation of electrocardiogram and echocardiogram before and after kidney transplantation (KT) in the Seoul National University Children���s Hospital. Results : Ten patients (Female 4, male 6) were investigated. Among them, 4 patients had eccentric LV hypertrophy, 5 patients had concentric LV hypertrophy, and 1 patient showed normal finding by echocardiography before KT. Mean age at present is 12.8 짹 4.3 years and KT was completed at their mean age of 9.7 짹 4.3 years. Mean follow-up periods was 3.14 짹 1.6 years. Among them, 3 patients are still taking anti-hypertensive medications for the persistent systemic hypertension. Mean systolic blood pressure is 113.1 짹 9.3 and diastolic pressure is 65.2 짹 8.7 mmHg. There were significant decrease of LV mass index (pre: 127.1 짹 51; post: 69.9 짹 19.2 g/m2, p=0.017) and increase of fractional shortening (pre: 28.5 짹 9.9; post: 37.9 짹 5.4%, p=0.028) after KT. Overall LV diastolic function showed improving tendency after KT (mean mitral valve E/A from 0.9/0.72 to 1.01/0.65 m/sec, p=0.161). LV Tei index did not show significant difference (pre: 0.41 짹 0.21; post: 0.39 짹 0.09, p=0.465). Although mean QTc interval (pre: 410 짹 38.2; post: 384.1 짹 21.9 msec, p=0.153) did not show significant difference, maximal QTc interval (pre: 443.7 짹 43.3; post: 406 짹 23.5 msec, p=0.032) and QTc dispersion (pre: 56 짹 18; post: 40.2 짹 12.3 msec, p=0.047) showed significant decrease after KT. Three among 4 patients who had eccentric LV hypertrophy are still showing mild LV diastolic dysfunction considering mitral inflow pattern despite normal LV dimension and systolic function. Conclusion : KT can reverse LV function, mass and QT prolongation in uremic cardiomyopathy. Despite good result of KT, meticulous cardiologic follow-up is needed in some patients.