Background: The aim of this study was to investigate the effect of Metabolic syndrome (MetS) on the success and complications of percutaneous nephrolithotomy (PNL). Methods: Two hundred ten patients who had undergone PNL for kidney stones in our clinic between May 2012 and May 2014 were retrospectively analyzed. The patients were divided into two groups based on whether they had diagnostic criteria for MetS. All patients had lower pole kidney stones between 15 and 20mm. Complication rates between groups were evaluated using a modified Clavien grading system. Results: Group1 was a standard PNL group and group 2 consisted of patients with MetS. Mean stone size was 293.25102.4mm(2) for group 1 and 301.10 +/- 169.5mm(2) for group 2 (p<0.05). Mean hospitalization days, fluoroscopy duration, and mean hematocrit loss were significantly higher in group 2. Mean operative time and need for blood transfusions were higher in group 2 but statistically insignificant. One hundred twenty five patients in group 1 (96.1%) and 72 patients in group 2 (90%) obtained stone-free state. Conclusions: Our study results reveal an increase in complications and morbidity for patients with MetS during PNL.