This study evaluated the reliability, internal structure, and validity of the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996) among female inmates (n = 153) housed at a multilevel prison facility. Findings from this research suggested both strengths and weaknesses associated with PPI psychopathy assessment. Reliability of the PPI was supported by internal consistency analyses of scale and subscale item sets, and test-retest reliability was supported by findings obtained with a subsample (n = 36) retested an average of 49 days after initial test administration. Validity of the PPI total score was also supported by moderate to very high correlations with other self-report measures of psychopathy. Relative weaknesses of the PPI were evident by the low or negative associations among many of the PPI subscales, moderate associations that PPI total scores demonstrated with response set indexes, and the similarity of PPI total scores among female inmates and undergraduates. Findings from this research are considered in relation to possible sex differences in the expression of psychopathy and challenges associated with the assessment of the psychopathy construct with self-report methods.