Diversion programs are initiatives in which persons with serious mental illness who are involved with the criminal justice system are redirected from traditional criminal justice pathways to the mental health and substance abuse treatment systems. This article is a review of the research literature conducted to determine whether the current evidence supports the use of diversion initiatives to reduce recidivism and to reduce incarceration among adults with serious mental illness with justice involvement. A structured literature search identified 21 publications or research papers for review that examined the criminal justice outcomes of various diversion models. The review revealed little evidence of the effectiveness of jail diversion in reducing recidivism among persons with serious mental illness. However, evidence was found that jail diversion initiatives can reduce the amount of jail time that persons with mental illness serve. Implications for practice and research are discussed.