 Extracorporeal shock wave lithotripsy is preferred for small stones less than 10 mm in size. Percutaneous nephrolithotomy is the standard therapy used for large kidney stones greater than 20 millimeters or stones in the lower kidney. For moderate sized kidney stone 10-20 mm,currently the options for treatment include both methods. However, no studies have proven that one procedure is better than the other. So, we will compare both the procedures for breaking the kidney stone. Our main outcome measures will be the stone-free status after the procedure. Other outcome measures are assessment of morbidity associated with use of the procedures i.e. any minor or major complications within 3 months of initial treatment. Patient will be assessed for infection at post-operative office visits to include a basic urinalysis only if they have systemic indicators of infection fever, dysuria, frequency, etc.. Pain will be monitored with the scale of 0-10 points. Also we will review of stone density on Computerized Tomography CT scans and the effect this has on success of both procedures. We hope with PCNL stone-free rates will be minimum with minimal morbidity and ultimately improve patient care. 