Abstract: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for kidney stones. In the PCNL procedure, artificial occlusion of the pelvic system and irrigation were performed. Although the irrigation process is performed with isotonic fluids, the PCNL procedure carries a risk of intravascular absorption of fluid. Apart from affecting hemodynamics, this can affect the amount of electrolytes before and after PCNL. The purpose of this study is to determine the difference between serum electrolytes in the conditions before and after the Percutaneous Nephrolithotomy (PCNL) procedure.