This article provides an overall summary of the results from four major studies under the Treatment Improvement Protocols (TIPs) evaluation project. The diffusion of innovations theory is used as a theoretical framework to understand substance abuse treatment providers' awareness, attitudes, and practices (or uses) of TIPs. Recommendations to improve the development and dissemination of TIPs are made. In addition, changes made to the TIPs program based on study findings are highlighted. All the studies within this project are structured around the diffusion of innovations theory framework and demonstrate the efficacy of theory-based program evaluation.