This study examined the internal structure and validity of the Psychopathic Personality Inventory (PPI) in a sample of 399 psychiatric inpatients. The construct validity of the PPI was examined by means of Confirmatory Factor Analysis (CFA). The divergent and convergent validity of the PPI were examined by correlating the PPI with demographic variables, intelligence, DSM-IV Axis I and Axis II disorders, and measures of impulsiveness, aggression, narcissism, and psychopathy. CFA supports the presumed 8-factor structure of the PPI and shows that the first-order PPI scales can be represented by two higher-order factors, that is, PPI-I (fearless dominance) and PPI-II (impulsive-aggressiveness). Males scored significantly higher on all PPI scales than females. PPI-I correlated positively with functional impulsiveness, amorality, social imperturbability, and self-centered narcissism. PPI-II was negatively related to age and educational level, and positively to physical and verbal aggression, dysfunctional impulsivity, and other-centered narcissism. Implications for clinical practice are outlined.