Favorable drug treatment outcomes are predicted by such factors as continuing in treatment, adherence to treatment regimens, and engagement in therapeutic processes. In turn, these factors are related in complex ways to the capability of treatment providers and the availability of resources; to patient factors such as motivation, suitability for treatment, and medical and psychological problems; and to external environmental events and influences. Innovative drug treatment approaches are described that attempt to build on a wide range of theoretical and clinical work to improve understanding of the treatment process and treatment outcomes. These approaches include outreach and enrolling high-risk populations in treatment, providing comprehensive treatment to those who need it, providing comprehensive AIDS education and behavioral change counseling, providing social skills and relapse prevention training, developing and testing improved counseling strategies, implementing and testing case management approaches, integrating treatment modalities, varying planned length of treatment, and providing continuity of care and transitional services in the criminal justice setting. Improved access to drug treatment is discussed in the context of methadone maintenance, residential treatment, case management, and multimodal and other eclectic programs. Specific attention is paid to HIV risk among injection drug users, cocaine addiction, cognitive and behavioral enhancements to community-based drug treatment, and the effect of treatment on high-risk sexual behavior and drug use. References, notes, tables, and figures