The Narcissistic Personality Inventory (NPI) is a widely used measure of narcissism. However, debates persist about its exact factor structure with researchers proposing solutions ranging from two to seven factors. The present research aimed to clarify the factor structure of the NPI and further illuminate its nomological network. Four studies provided support for a three-factor model consisting of the dimensions of Leadership/Authority, Grandiose Exhibitionism, and Entitlement/Exploitativeness. The Leadership/Authority dimension was generally linked to adaptive outcomes whereas the other two dimensions, particularly Entitlement/Exploitativeness, were generally linked to maladaptive outcomes. These results suggest that researchers interested in the psychological and behavioral outcomes associated with the NPI should examine correlates at the facet level. In light of the findings, we propose a hierarchical model for the structure of the NPI and provide researchers with a scoring scheme for this commonly used instrument. (Contains 1 figure, 8 tables and 7 notes.)