In this study, 16 different substance abuse and delinquency prevention programs were successfully implemented by 12 intervention communities using the Communities That Care (CTC) prevention system. Large proportions of required material were taught and core components delivered, nearly all lessons were offered in accord with the length and frequency specified by program developers, implementers were prepared and enthusiastic and used a variety of teaching techniques to convey material, and high levels of engagement from program participants were observed. Despite noted limitations, the findings reveal that communities participating in this study and using this system of program monitoring implemented selected prevention programs in strong accordance to the theory, content, and methods specified by program developers. There is mixed evidence regarding the extent to which communities can replicate science-based substance use and delinquency prevention programs with high implementation commitment. The study also provided a general methodology and measurement tools that can be used by community prevention coalitions. Tables, notes, and references