The Saughton Drug Reduction Program was developed because of recognition that many offenders entering the prison are heavy drug users; a significant proportion of them are also HIV infected. The program offers education and counseling options, with input from a multidisciplinary team of prison personnel and outside agency representatives. The analysis revealed that the program has become widely accepted within the prison a year after its beginning. In addition, compared to a matched control group, drug treatment clients reported lower drug use on a variety of measures. Moreover, they maintained this difference throughout their current sentence. A future part of the evaluation will determine the impact on clients' drug use after release. Findings indicated that the program provides a model that could be adopted by other prisons in the United Kingdom. Tables and 52 references