Pretreatment factors include client characteristics such as age, gender, and race/ethnicity. If programs are to be effective, they must take these factors into account in program content and/or delivery style. The benefit of designing gender-specific and racial-specific treatment programs is that the relevance of the program to the youth maximizes client retention and enhances program performance. In-treatment factors relate to the process of program administration, including program content and delivery aspects as well as more external considerations such as the organizational environment in which the program is delivered. The literature indicates that for programs to be effective, they must target the multiple needs of young offenders, which typically are in the domains of family, school, and peer relationships. A focus on relapse prevention is also a key to treatment effectiveness. Behavioral/cognitive-behavioral methods for delivering program content have proven to be most effective. Programs are also more likely to be effective when delivered in the community compared to residential custodial settings. Program integrity, another key element of effective programs, is best achieved through appropriate training and monitoring of program staff. Post-treatment factors relate to monitoring and services provided by criminal justice agencies once the client has completed the program. Two of the most important factors are the provision of aftercare services and the identification and enhancement of protective factors. The few studies that have examined the effectiveness of aftercare services within a correctional population have found mild reductions in recidivism; however, data are too limited to draw firm conclusions in this area. Other important issues addressed in the literature are the high rate of program dropout, the high rate of HIV/AIDS in correctional populations, and how to define an effective program. Regarding the latter topic, recommendations have suggested that programs use classical experimental evaluation designs that have stringent controls in measuring program impacts across a number of areas, including physical, emotional, and behavioral outcomes. Suggestions for future research include the use of focus groups of young offenders across Canada to identify potentially motivating and detrimental factors that affect their involvement in treatment. The incorporation of protective factors in treatment should also receive additional research. This paper includes a checklist that can be used by program administrators to develop effective substance abuse programming. 156 references