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Background and Aim: Surgery for removal of urinary system stones has improved very much. At the present time standard therapy for stones which do not respond to ESWL, and also for large or multiple stones is PCNL. In this method the stones are broken into small pieces and taken out. This method has a better outcome and minimal morbidity rate. The aim of this study was to assess the outcome of PCNL operations in Kurdistan province since 1383. Materials and Methods: This was a cross sectional descriptive analytic study. The study group comprised all the patients who had undergone PCNL from 1383 to 1385 (100 patients). Sampling method was census. Data collected by reviewing the patients` medical records and were registered in check lists. The collected data were analyzed by means of 2 and T-test using SPSS win soft ware. Results: from 1383 to 1385, 100 PCNL operations had been done on 66 (66%) men and 34 (34%) women. The mean age of the patients was 38.33±12.81. (age rang: 17-72 years old). The mean operation time was 86.91±24.12 minutes and the mean size of the stones was 33.72±9.81mm. The mean hospitalization time was 2.33±0.65 days and the mean narcotic (petidin) dose was 57.6±24. 17% of the patients developed some kind of complication, but no problem observed in the other 83%. In general 91% of the operations were successful. 2% of the patients needed another surgery and in 7% of the patients, the remaining stones were treated by use of ESWL. The most common type of stones were calcium oxalate. There was a significant relationship between the operation time, dose of narcotic and duration of hospitalization (p=0.000). Conclusion: The result of this study were compatible with previous studies and confirms PCNL as a successful surgical method for treatment of the urinary system stones.