Patients appear to have the best chance for successful SWL when they have small BMI and their stones are single and located in the renal pelvis . Skin to stone distance (SSD) measured by non-contrast computerized tomography scan (NCCT) has a significant role in the treatment of renal stones using SWL. Slow shock wave rate (60/min) is associated with increase in the success rate and decrease in pain, complication and number of session to achieve success when compared to rapid shock wave rate (120/min)