Before introducing an HIV testing protocol into correctional facilities, the unique nature of these environments must be taken into account. We analyze three testing strategies that have been used in correctional settings--mandatory, voluntary, and routine "opt out" testing--and conclude that routine testing is most likely beneficial to inmates, the correctional system, and the outside community. The ethics of pre-release testing, and the issues surrounding segregation, confidentiality, and linking prisoners with community-based care, also play a role in determining how best to establish HIV testing strategies in correctional facilities. Testing must be performed in a manner that is not simply beneficial to public health, but also enhances the safety and health status of individual inmates. Longer-stay prison settings provide ample opportunities not just for testing but also for in-depth counseling, mental health and substance abuse treatment, and antiretroviral therapy. Jails present added complexities because of their shorter stay with respect to prisons, and testing, treatment, and counseling policies must be adapted to these settings.