Aggression, as viewed in the study, involves a drive toward autonomy and the meeting of personal needs; therefore, it is not a negative trait per se. When the goals of aggression are thwarted, varying levels of hostility are generated; these traits are therefore linked but are not synonymous. A sample of 240 inmates was matched with an equal number of noncriminals on the variables of age, education, marital status, and residence (rural or urban). Within the criminal group, property offenders were compared in aggressiveness with those who committed crimes against persons, and recidivists were compared with first offenders. In order to measure aggression, a five-trait inventory with forced-choice format of items was used; the inventory has shown high indices of reliability and validity. The chi-square test was used in the comparisons. Findings show that the inmates scored slightly higher in aggression when compared to the matched sample of noncriminals, although the difference was not statistically significant; however, those who committed crimes against persons were found to be significantly more aggressive than property offenders, and recidivists were significantly more aggressive than first offenders. While the trait of aggressiveness is not negative per se, there are indications that those criminals who possess high levels of aggressiveness need strong and consistent conditioning and guidance that will equip them to channel and control their aggressiveness for constructive purposes. A total of 11 references and tabular data derived from the study are provided.