The article highlights two successful, prison-based drug treatment programs that incorporate cognitive interventions and provide a controlled outcome evaluation, namely, the Stay'n Out program operating in the New York State correctional system and Time to Think, the Correctional Service of Canada program. All Stay'n Out program activities encourage, and in some instances coerce, participants to examine their ways of thinking and behaving and to develop and practice alternatives to their established behaviors. Followup evaluations provide support for Stay'n Out's efficacy. Time to Think targets the thinking and social skills deficits frequently found in substance abusing and offender populations. Focusing on changing how offenders think, Time to Think provides training in specific areas such as problem- solving thinking, social and communication skills, negotiation, critical reasoning, handling emotions, and thinking creatively. Twenty percent of 40 offenders who had completed the program and were released to the community were rearrested compared to 30 percent for a comparison group. 58 references