Thailand's prisons are overcrowded, house many prisoners at high risk of HIV infection, and have a high turn-over of prisoners. Prevention and management of HIV is therefore important both for prisoners and staff and for the wider population. It is argued that although HIV/AIDS policy in Thailand's correctional institutions has often lagged behind policy developments in the wider Thai society it has nevertheless become more liberalised. Segregation and testing have been abandoned in favour of education and universal preventative precautions. Problems with financial and human resources continue to hamper the effective implementation of policy. There is also a greater need for co-operation between correctional services and non-government organisations to support HIV-positive prisoners upon their release.