Prison violence is a major concern in most correctional institutions. One intervention frequently used to reduce violent behavior is cognitive therapy. An involuntary cognitive program at a Midwestern state prison was evaluated for its impact on official misconduct. A total of 213 inmates were randomly assigned to the treatment (CHANGE) group (n = 122) and the control group (n = 91). The specific outcomes measured were disobeying a direct order, insolence, violent, nonviolent, and total number of infractions. Using general linear univariate model analyses, the only statistically significant but important difference found was the reduction of violence for the CHANGE group after 6 months. (Contains 5 tables.)