Objectives: Management of the kidney stones can be a challenge especially in obese patients, in this study we evaluated the results of flexible urs success rates in obese patients. Material And Methods: Retrospective regarding of the 107 kidney stones patients who performed flexible ureteroscopy in our clinics between December 2012 with February 2016. Patients were categorised according to WHO BMI classification. Fluoroscopy time, operative time, complications that occur during the procedure were recorded. Overall stone-free rates were evaluated after the four weeks later the operation by taking the KUB or Abdomen CT. All procedures were performed under general anaesthesia using with the three different flexible ureteroscopy and Ho:Yag Laser. Except to two patient, we used access sheats in all patients. We analysed the dates with using IBM SPSS 21 software. Result: There were no statistically significant differences in the frequency of among these groups (p > 0.05); when to compare the operative, fluoroscopy and hospitalisation time and stone-free rates between of groups. The overall mean stone volume was 337.2 +/- 231. 5 mm3, mean operative time was 79.6 +/- 22.6 minutes, average fluoroscopy time was 12.8+/- 17.5 second and hospitalisation time is 34 +/-25.9 hour. Average operative time was measured (77.7 +/-20.7 min) in the obese two as the shortest one. The shortest average fluoroscopy time ( 8.18+/-8.83 sec ) was taken in obese two group. Same statistical insignificance was attained about the hospitalisation time; the overweight group had the shortest duration (31.68 +/- 25.2 hours ). Moreover, we analysed the stone free rates; respectively we got relatively high success rates in obese 1 ( %75.9 ), obese 2 ( %72.7) compare the others but it also was not statistically significant. Conclusion: Flexible Urs is a powerful treatment modality in the kidney stone patients, irrespective of the body mass index. Based on the body weight, make predictions about the operation, fluoroscopy and hospitalisation time and stone free rates shouldn't be recommended.