Unlike its other Asian counterparts, the national prioritizing of HIV/AIDS in Thailand, through the development of a number of preventive initiatives, has resulted in a declining rate of incidence. While there are no laws overtly protecting the rights of people living with HIV/AIDS (PLWHA), substantial written policy has been enacted. Yet in spite of this highly protective legislative and policy environment, discrimination against PLWHA continues to occur in practice. Focusing on the healthcare sector, through the framework set out in the UNAIDS 'Protocol for the Identification of Discrimination against People Living with HIV' (the Protocol) this study found that discriminatory attitudes and practices arose primarily due to a lack of appropriate monitoring of levels of compliance by health care providers. The disparity between written policy and practice can be explained by the underlying personal and cultural factors and the authors strongly contend that for written policies to effectively work, further research needs to be conducted into the individual and cultural values of Thai health personnel.