The study compared a total of 123 randomly selected inmates who participated in other self-help programs and randomly selected inmates who participated in the first phase of a cognitive restructuring program with inmates who had been in the second phase for at least 6 months. The cognitive restructuring program, Strategies for Thinking Productively (STP), focused on disciplinary infractions. Participation in the first phase appeared to reduce refusals to obey a direct order, whereas participation in the second phase appeared to reduce assaults. However, there were no significant differences in the total number of incidents of major misconduct. The STP program, by reducing inmate assaults and the disobeying of direct orders, can help make the prison a safer, more orderly environment. Reductions in associated sanctions such as days in detention and number of days lost also can help reduce prison operating costs. Tables, references