As used in this review, "rehabilitation" refers to "those types of practice in juvenile justice that are most directly aimed at reducing reoffending in juveniles and is used to refer to specific forms of intervention rather than the social or administrative context in which interventions take place." A review of the published literature notes two broad conclusions from a number of meta-analytic reviews from around the world. First, there is substantial evidence that suggests interventions to reduce reoffending by juveniles lead to positive outcomes based on a comparison of treated groups with nontreated groups. Second, some interventions have significantly more positive impacts than others. Following the literature review, the five basic principles of good rehabilitative practice are outlined. A discussion of the "what works" approach to offender rehabilitation considers the principles of risk, needs, responsivity, program integrity, and professional discretion. Measures of effective interventions are also discussed, along with cost-effectiveness and best practice in rehabilitation programs. Another major part of this review distinguishes between rehabilitation programs that target specific types of offending and those that target criminogenic needs; methods of program delivery are also addressed. A section on issues related to specific groups within juvenile justice focuses on age groups, young women, ethnicity, and youth with disabilities. In the summary section, the review concludes that much more work is required in matching interventions to individual needs. 400 references and an appended bibliography of the Australian Institute of Criminology database of juvenile rehabilitation programs