The National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) is designed to test drug abuse treatment interventions in multisite clinical trials and to support the translation of effective interventions into practice. In this study, qualitative methods were applied to examine adoption of motivational interviewing and motivational enhancement therapy (MI/MET) in five clinics where these interventions were tested. Participants were clinic staff (n=17) who were interviewed about the MI/MET study, and about whether MI/MET was adopted after the study ended. Although clinics' participation in a clinical trial includes many elements thought to be necessary for later adoption of the intervention, we found that there was "adoption" in one clinic, "partial adoption" in one clinic, "counselor adoption" in one clinic, and "no adoption" in two clinics. These findings highlight a distinction between adoption at the organizational and counselor levels, and suggest that a range of adoption outcomes may be observed in the field. Findings are relevant to clinical staff, program directors, administrators and policy makers concerned with improvement of drug abuse treatment systems through adoption of evidence-based practices.