The need for offender drug treatment is evidenced in the fact that although a large proportion of the Nation's offenders lead lifestyles that include drug abuse, only a small percentage receive treatment while in the criminal justice system. Regarding the effectiveness of offender substance abuse treatment, a 5-year study of the "Stay'n Out" prison therapeutic community indicates that this program is effective in reducing recidivism rates. Project "Reform" was one of an array of technical assistance projects established to implement funding for drug treatment programs under the Anti-Drug Abuse Act of 1986. During the 5 years of Project Reform operations (1987-91), the 11 participating State departments of correction developed State plans and implemented many substance abuse initiatives. Project Recovery continued technical assistance from Project Reform for 18 months (1991-92). Both projects were guided by general principles of successful correctional intervention developed on the basis of clinical experience in the field of drug abuse treatment in corrections and a review of the existing drug abuse research and treatment literature. This paper presents the principles on three levels: State, institutional, and individual. A summary of new directions in prison drug treatment is based on the recommendations of a panel of national leaders, policymakers, and practitioners who represent the fields of corrections, social services, and substance abuse. 44 references