Mail questionnaires were sent, from November 1991 through June 1992, to individual officers of both genders working in six male penitentiaries within a northeastern State Department of Corrections. The questionnaire partially replicated an earlier study of COs and was based on the Critical Incidents Scale (CIS) developed by Kercher and Martin and used by Crouch and Alpert, as well as an 11-item Likert-type scale that measured control issues. A sample of the women respondents participated in a follow-up telephone interview. The CIS was designed to measure aggressiveness in inmate encounters through a series of hypothetical but realistic prison confrontational situations. findings show that most volatile incidents did not manifest significant gender differences in aggression. Where differences did exist, they were in the opposite direction from that commonly assumed; the women COs tended to be more aggressive than the male COs. The study concludes that occupational socialization and the demands of the job account for the similarities between genders, and the differences result from the gender-specific barriers that confront women officers. Overall, women COs neither increase nor decrease the rate of violence in prisons and are as effective at handling inmate incidents as male officers. Further research must address the discrepancy between previous studies and current findings. 4 tables, 1 note, and 23 references