The aim of this study was to show the advantages of body temperature irrigation fluid in ureteroscopy compared to room temperature fluid. A total of 94 patients with radio-opaque single ureteral stone whom scheduled for semirigid ureteroscopy were enrolled into this study. Patients were randomized into 2 groups: Group 1, ureteroscopy with room temperature irrigation fluid (20-22 ºC) and Group 2, ureteroscopy with body temperature (37 ºC) irrigation fluid. Patient characteristics (age, sex), stone characteristics (stone side, stone location, stone burden, Hounsfield unit), operation outcomes (operation time, ureteral JJ stenting, complications, stone free rate at 4 weeks, auxiliary intervention need, visual analogue score) were analyzed. There was no statistically significant difference between two groups regarding patient characteristics and stone characteristics. Operation time was found to be shorter in Group 2 compared to Group 1 (p: 0.02). Post-operative pain was also less common in Group 2 compared to Group 1 (p<0.001). Complication rates was 17% in Group 1 and 8% in Group 2 but no statistically significant difference was found. Body temperature irrigation fluid in ureteroscopy is beneficial because: it facilitates easier ureteral access by decreasing ureteral spasms, shortens operation times, lowers post-operative pain and lowers the complications rates. This method can be used in semirigid ureteroscopy since it is an easily applicable method with no known associated complications.