Objective: The aim of this study was to compare demographic data in adult patients undergoing percutane-ous nephrolithotomy (PNL) for kidney stone disease in university hospitals from Southeastern Anatolia andthe Black Sea regions.Material and methods: The demographic data of 535 (53.3%) patients undergoing PNL from GaziantepUniversity, Department of Urology (GAUN group), and 468 (46.6%) patients undergoing PNL from On-dokuz Mayıs University, Department of Urology (OMU group) were evaluated retrospectively. Patients gender, mean age, stone laterality, and size and results of the stone analyses were compared.Results: The mean patient ages were 40.94±13.33 (17-81) and 48.03±13.95 (17-81) years in the GAUN and OMUGroups, respectively, (p=0.0001). The mean stone size was 716.01±449.60 (100-3000) mm 2 and 612.7±445.87(65-3220) mm 2 in the GAUN and OMU Groups, respectively (p=0.0001). There were no statistically signifcantdifferences between the groups with respect to stone laterality (p=0.196), and gender of the patients (p=0.65).Stone analysis revealed that the distribution of stone composition was as follows in the GAUN group: Ca oxa-late (90.19%), cystine (7.84%), uric acid (5.88%), and struvite (1.96%). In the OMU group, the stone composi-tion was as follows: Ca oxalate (86.84%), cystine (1.34%), uric acid (13.15%), and struvite (9.21%).Conclusion: The incidence of kidney stone disease varies throughout Turkey based on etiological factors,and a higher incidence of kidney stone disease is observed in the Southeastern Anatolia region endemically.Lower mean ages and higher stone sizes in patients undergoing PNL in southeastern Anatolia suggest thatgeographic factors can affect stone disease.