This study investigates the effectiveness of the Rhode Island Adult Drug Court. It examines the impact of the treatment modalities offered by the Drug Court on participants’ likelihood of graduating successfully from the program. Anonymous, public data on the 71 participants in the Rhode Island Adult Drug Court during the 2005-6 court cycle provided the basis for the study. Data examined include clients’ demographic characteristics, the type of offense for which each was charged (drug related or non-drug related), and also the type of treatment in which the participant was engaged at the beginning of his or her participation in the program. The study uses cross-tabulation, correlation and logistic regression analysis to evaluate the impact of client characteristics and court ordered treatment modalities on the likelihood of clients’ graduation or failure from the program.