Hemodialysis (HD) patients are known to have high cardiovascular mortality rate. Sudden cardiac death (SCD) due to arrhythmias causes most of the cardiac deaths. HD per se may lead to ECG abnormalities and ventricular arrhythmias. Monitoring ECG parameters such as corrected QT interval, QT dispersion (QTd), Tpe interval may be useful to stratify the patients with high risk of arrhythmia and SCD. Herein we aimed to investigate the effects of changes in serum electrolyte levels and pH on ECG parameters before and after the HD.