The five-factor narcissism inventory (FFNI) is a new self-report measure that was developed to assess traits associated with narcissistic personality disorder (NPD), as well as grandiose and vulnerable narcissism from a five-factor model (FFM) perspective. In the current study, the FFNI was examined in relation to Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV; American Psychiatric Association, 2000) NPD, DSM-5 (http://www.dsm5.org) NPD traits, grandiose narcissism, and vulnerable narcissism in both community (N = 287) and clinical samples (N = 98). Across the samples, the FFNI scales manifested good convergent and discriminant validity such that FFNI scales derived from FFM neuroticism were primarily related to vulnerable narcissism scores, scales derived from FFM extraversion were primarily related to grandiose scores, and FFNI scales derived from FFM agreeableness were related to both narcissism dimensions, as well as the DSM-IV and DSM-5 NPD scores. The FFNI grandiose and vulnerable narcissism composites also demonstrated incremental validity in the statistical prediction of these scores, above and beyond existing measures of DSM NPD, grandiose narcissism, and vulnerable narcissism, respectively. The FFNI is a promising measure that provides a comprehensive assessment of narcissistic pathology while maintaining ties to the significant general personality literature on the FFM.