Objective: the aim of the present research was to determine the reliability and validity of the Persian version of Pathological Narcissism Inventory (PNI). Method: In this descriptive study, 682 students (292 female, 390 male) were selected through the multistage cluster sampling method from different universities in Tehran and Pathological Narcissism Inventory was administered to them. Cronbach’s alpha, test-retest reliability, and confirmatory factor analysis were used to determine reliability and validity of Pathological Narcissism Inventory. Results: The test-retest correlation coefficient for the total scale was 0.90. The cronbach's alpha of the total scale was 0.95 and ranged from 0.78 to 0.92 for its components. Results of first-order confirmatory factor analysis indicated that seven component of PNI load on one factor and seven-factor model fit in Iranian sample. Also, Results of two-order confirmatory factor analysis showed that seven components of PNI load on narcissistic grandiosity and narcissistic vulnerability factors and two-factor model has an acceptable fitness. Conclusion: The obtained results, replicated findings of previous researches and supported the seven first-order factors and two second- order factors of PNI structure. Considering results of this study, the Persian version of the Pathological Narcissism Inventory possess suitable reliability and validity in order to assess the pathological narcissism in Iranian sample.