In general, the article notes that mandated treatment was found to be ineffective in several analyses, particularly when the treatment was located in custodial settings, whereas voluntary treatment produced significant treatment effect sizes regardless of setting. Few significant differences in effect sizes were found between levels of coercion. Regarding coercion, it is noted that true voluntary participation did not exist in the criminal justice system because there was always some degree of external pressure. Mandating offenders to attend correctional treatment is said to be a controversial function of the justice system, in part because of the uncertainty about the effectiveness of such practice. The various implications of mandating correctional treatment for offenders are also discussed. The information for this article was derived from a meta-analysis of existing literature conducted to compare the effectiveness of mandated, coerced, and voluntary correctional treatment in reducing recidivism. More than 500 studies were identified in the initial search, with the final tally of correctional treatment studies resulting in 129 studies that met the inclusion criteria. Of these, 33 percent involved exclusively mandated treatment programs. Over 59 percent involved exclusively non-mandated treatment programs, and 7 percent were mixed. Tables, figure, notes, and references