This collection reports on the progress of the intervention programs first described in Innovative Approaches in the Treatment of Drug Abuse: Program Models and Strategies (Inciardi and Fletcher, 1993). By examining the implementation of treatment initiatives, this study focuses on an area often neglected in the research literature: the context in which research is conducted. Applied researchers, particularly those who study users of illicit drugs, face many obstacles that investigators working in more controlled settings, or with more predictable and compliant subjects, often do not encounter. These accounts demonstrate the challenges in producing rapid improvement in treatment for the vulnerable and underserved population of drug abusers. A close study of these efforts will be useful to other researchers in planning for and solving implementation problems that can be anticipated, and in providing guidelines and strategies to overcome those that cannot.