Objectives We report the results of a multilevel structural equation model of the Multisite Adult Drug Court Evaluation that empirically tests theoretical pathways to desistance from drug use and criminal behavior. Methods First, we consider how to operationalize the theoretical mechanisms through which drug court practices are meant to impact outcomes. A path model is proposed that delineates how drug-court practices change perceptions and attitudes, and how these changes subsequently affect drug use and crime. Proposed mediators include changes in court practices (e.g., court appearances, drug testing, and treatment) and psychological mediators, including perceived risk and reward (deterrence), perceived legitimacy (procedural justice), and motivation to change one's behavior through substance abuse treatment. Results Results suggest that one element of procedural justice, the clients' attitude toward the judge, is the most crucial theoretical mediator on the pathway to desistance from drug use and crime. Conclusions Study limitations and directions for future research are discussed.