The National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) was established in 1999 to determine effectiveness of drug abuse treatment interventions among diverse client populations and settings. To address dissemination of research findings, the CTN also has as its mission the transfer of research findings to treatment providers. In a qualitative study of adoption of evidence based practice in the context of two CTN clinical trials, we interviewed 29 participants from seven organizational levels of the multisite study organization about post-trial adoption, their role in the clinical trial, and interactions between the research initiative and clinic staff and setting. Analysis of interview data revealed a range of opinion among participants on the place of adoption within the CTN. Innovation within the CTN to support adoption and further observational research on dynamics of adoption within the CTN can increase dissemination of evidence-based drug abuse treatment interventions in the future.