The interventions included arrest referral programs, probation referral programs, and efforts in prison. Data came from a review of 2,078 referral/assessment records, 322 interviews with drug-using offenders who had contact with criminal justice drug workers (CJDW), 21 detailed interviews with crucial professionals, and field notes made at management and worker meetings. Those passing through the schemes tended to be white male opiate/polydrug users in their late 20's or early 30's. CJDW's referred three-fourths of those they saw to drug services. Half of those they saw entered drug programs, most involving counseling and half including substitute prescribing. The participants interviewed 6-9 months after contact with CJDW's had positive attitudes toward the help they had received and reported large declines in their use of opiates and in drug expenditures. No significant changes occurred in employment, housing, or personal relationships. Findings called into question the simple opinion that drug use draws people into a life of crime and suggested that well-designed referral systems can break the cycle of parallel drug and crime careers. Findings indicated that arrest referral systems, probation referral systems, and work in prisons can identify drug abusers as they pass through the criminal justice system, refer them to treatment agencies, and produce consequent reductions in drug use and drug-related crime. Tables, figures, footnotes, appended additional results, and 17 references