Objective: The purpose of the present study is to provide data on the outcomes of ureterorenoscopic management of lower pole kidney stones in a variety of composition and size.

Materials and Methods: Data of patients with lower pole kidney stones who underwent retrograde intrarenal surgery (RIRS) in Siriraj hospital between 1st June 2012 to 30th April 2017 were retrospectively reviewed and analyzed data consists of demographic information, stone size, stone free rates, complications and auxiliary procedures.

Results: 103 patients with lower pole kidney stones from 423 patients who underwent RIRS in Siriraj Hospital. 61 patients (59.2%) achieve stone-free status within 3 months after surgery. Stone free rates of RIRS were 72.2%, 69.8% and 42.9% in stone size less than 10 mm, 10 to 20 mm and larger than 20 mm respectively.

Conclusion: RIRS is a safe and effective treatment in lower pole renal calculi with high success rate and low morbidity.

Keywords: Retrograde intrarenal surgery, Flexible ureterorenoscopy, Lower pole, Renal calculi, Stone free rate