The current study was conducted over a 6-month period, beginning in February 1994 and ending on July 30, 1994. A survey inventory designed to capture the specifics of officer assaults was developed. The Federal Bureau of Prisons and 21 adult State correctional departments agreed to participate in the study. The response rate was 43 percent. The sample size included 53 correctional institutions and 604 assaultive incidents; only male institutions were studied. Data include encompass the demographics of the institutions, location of assault incidents, characteristics of the inmate, type of inmate assault, officer characteristics, and circumstances of the assault. Findings show that younger inmates with a mean age of 26 years are more likely to assault officers. The inmate is normally 10 years younger than the corrections officer who is assaulted. A significant number of officer assaults occur during the performance of basic job tasks, such as enforcing institutional rules, giving orders, conducting searches, and supervising inmates. Officers are likely to be assaulted with a personal weapon, ranging from a punch, slap, kick, grab, or wrestling situation; the most serious injury sustained by an officer is usually a back injury or a fracture of the hand or arm. Officers who have from 5 to 8 years of experience and are between the ages of 30 and 45 are more likely to be assaulted. Implications of these findings and suggested policies for countering inmate assaults are discussed. 2 figures, 1 table, and 11 references