The conceptual framework described was developed by the National Evaluation of Juvenile Drug Courts project at the Urban Institute. It specifies the conceptual underpinnings of drug court activities and identifies causal mechanisms that might enable these activities to achieve program outcomes. The framework does this by specifying the chain of events that begins with program activities and ends with program outcomes. It identifies hypothesized links among juvenile drug court practices; systems of treatment; and key outcomes such as treatment participation, client retention, and program graduation. The framework describes how juvenile drug courts might change offender behavior. Researchers should thus use it to narrow the scope of future juvenile drug court evaluations and identify case processing and service delivery variables that are closely connected to program effectiveness. This will help in refining empirical assumptions about juvenile drug court operations, guide the measurement of key influences on offender behavior, and develop data-collection methods for evaluation studies. Given the diverse policies and practices of juvenile drug courts that are operating under the general drug court model, it is not particularly helpful to other drug courts when an evaluated drug court shows evidence of desired outcomes. Widespread improvement in the effectiveness of juvenile drug court operations requires that evaluations make connections between specific drug court policies and procedures and the outcomes achieved. The conceptual framework proposed in this paper could help future evaluation studies focus on identifying and explaining differences in the success of varying juvenile court models while determining those aspects of the court process most related to outcomes. 2 tables, 1 figure, and 61 references