This study evaluated the effectiveness of a National Institute of Corrections' cognitive-behavioral program for adult offenders, entitled "Thinking for a Change." One hundred male and 42 female probationers were studied. Probationers assigned to the "Thinking for a Change" program were matched with a comparison group not assigned to the program and contrasted on interpersonal problem-solving skills pre- and post-program completion, and on recidivism at three months to one year post-program. Results indicate a trend towards lower recidivism, with 33% fewer subjects who completed the program committing new offenses, compared to those who did not attend the program, over a period of up to 12 months. Technical violations of probation were significantly higher for program dropouts than for completers or comparisons. Program completers improved significantly on interpersonal problem-solving skills after "Thinking for a Change," while the dropout and comparison groups had no such gains. (Contains 2 figures.)