Prior research has examined the relationship between personality characteristics and problematic behaviors, suggesting the utility of self-report personality measures in assessing risk of aggression. This study examined the relationship between select Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) scales and estimated psychopathy indices derived from MMPI-2-RF scales, and institutional aggression among hospitalized pre-trial defendants. Scores on Thought Dysfunction (THD), Aberrant Experiences, Juvenile Conduct Problems, and Psychoticism-Revised (PSYC-r) were associated with mild-severe aggression. Similarly, THD and PSYC-r were associated with moderate-severe aggression. Regarding psychopathy, impulsive-antisociality, but not fearless-dominance, was associated with both aggressive outcomes. Overall, the relevant MMPI-2-RF scales demonstrated higher classification accuracy than the estimated psychopathy indices.