We are trying to study the ability of CCI to predict post-operative morbidity and mortality after PCNL. This is a prospective study carried out on 300 patients with renal stones candidate for PCNL in two centers. CCI was calculated for every patient prior to the procedure and total score was given to him for his co-morbidities. Our results showed that co-morbidity increases with increase of the patients age, higher CCI score was not associate with the rate of post-operative surgical, medical complications and mortality.Conclusion: Charlson co-morbidity index was not found to be predictive after percutaneous Nephrolithotomy.