Objectives: To evaluate the alleviation of hydronephrosis by ultrasonography in patients after retroperitoneal laparoscopic ureterolithotomy with indwelling JJ stent. Patients and methods: Cross-sectional study in patients who underwent retroperitoneal laparoscopic ureterolithotomy with indwelling JJ stent from 3/2010 to 4/2011 at Cantho General Hospital. Results: 33 patients after retroperitoneal laparoscopic ureterolithotomy with indwelling JJ stent were evaluated the alleviation of hydronephrosis by ultrasonography.