Relevant journal publications and conference presentations were identified through a comprehensive search of electronic databases. Experts involved in the development and evaluation of current prison-based syringe exchange (PSE) programs or policy were contacted for official reports, policy documents, or unpublished materials. Information collected from interviews with five experts was added as supplementary data to the reported literature. As of December 2000, 19 PSE programs had been identified in Switzerland, Germany, and Spain. Switzerland was the first country to initiate a PSE program (1992). This paper provides details on the development and operation of PSE programs in each of these three countries. Three different methods of distributing injecting equipment were identified. Six of the 19 programs had been evaluated, yielding positive results. Conclusions from all evaluations indicated that PSEs were feasible. The evaluations emphasized the need for collaborative efforts in design and development among all groups affected by the program. They also emphasized the need for integrating PSE programs within a wide range of education and harm-reduction activities. The primary objective of PSEs has been to reduce blood-borne viral infections in prison. These programs have apparently achieved this, since no new cases of HIV, hepatitis C, or hepatitis B were reported in any evaluation. Swiss evaluations found a reduction in drug use at two follow-ups. The German evaluation also noted a satisfactory integration of the PSE into the health system and an increase in referrals to drug treatment. The authors advise that the overall success of the evaluated PSE programs in Europe suggests that similar programs may be beneficial in any correctional settings with a high rate of injecting drug use. 2 tables and 23 references