Summarizing the outcome of a number of meta-analyses of correctional program elements that are effective in reducing recidivism, Gendreau (1996) has proposed a set of eight principles of effective program design. The principles are outlined in this paper, and examples are provided of how the principles are implemented in programs currently being delivered by the Correctional Service of Canada. Examples of treatment approaches address stages of change, relapse prevention, motivational interviewing, and harm reduction. Stages of change pertains to a model of readiness to change that allows treatment providers to match treatment to an individual's willingness to change. The goals of relapse prevention are to provide information useful in recognizing high-risk situations that may lead to relapse and then providing the skills needed to deal with the relapse when it occurs. Motivational interviewing is a technique of interactive communication that helps people recognize and do something about a current or potential problem. It is particularly useful with people who are reluctant to change or are ambivalent about changing. Harm reduction is an approach to intervention that aims to reduce the negative consequences of substance abuse to the individual and to society. Another section of the paper addresses the features of research that are needed in measuring a program's impact on recidivism, followed by examples of programs being conducted by the Correctional Service of Canada and the status of their evaluations. The programs include the Women Offenders Substance Abuse Program, intensive support units, methadone maintenance treatment, and the High Intensity Substance Abuse Program. 1 table and 2 figures