The U.S. correctional system is overburdened with individuals suffering from substance use disorders. These illnesses also exact a heavy toll on individual and public health and well-being. Effective methods for reducing the negative impact of substance use disorders comprise critical concerns for policy makers. Drug treatment court (DTC) programs are present in more than 1800 county, tribal, and territorial jurisdictions in the United States as an alternative to incarceration for offenders with substance use disorders. This review article summarizes the available descriptive information on representative DTC populations and the observational studies of drug court participants, and it specifically reviews the available experimental effectiveness literature on DTCs. The review concludes by examining the limitations of the current literature, challenges to conducting research in drug court samples, and potential future directions for research on DTC interventions. A review of nonexperimental and quasi-experimental literature regarding the impact of DTCs points toward benefit versus traditional adjudication in averting future criminal behavior and in reducing future substance use, at least in the short term. Randomized effectiveness studies of DTCs are scant (3 were identified in the literature on U.S. adult drug courts), and methodological issues develop in combining their findings. These randomized trials failed to demonstrate a consistent effect on rearrest rates for drug-involved offenders participating in DTC versus typical adjudication. The 2 studies examining reconviction and reincarceration, however, demonstrated reductions for the DTC group versus those typically adjudicated.