Despite the advancement in highly active antiretroviral therapy and improved health status of HIV-infected individuals, dental problems are still affecting their life and well-beings. We aimed to establish the prevalence of oral and dental complaints among HIV-infected patients, the prevalence of delayed access to dental service, and factors related with delayed access to dental service. A cross-sectional study using self-report questionnaire completed by the HIV-positive subjects was conducted at the largest HIV research clinic in Thailand during 2009-2010. Of all 299 subjects (28.6% males, 71% females, and 0.4% sex change from male to female: ages ranged from 22 to 59 years [mean 36.7±5.53)]), 84.3% reported of having past or present illnesses or problems related to the dental or oral conditions. The most reported problems were dental hypersensitivity (93.3%), bleeding from the gum (92.1%), and having dental caries (65.9%). Two-hundred and forty-two subjects (80.9%) would not disclose their HIV status when seeing a dentist. The most cited reasons of such behavior were their personal right whether to reveal or not, and being afraid of not receiving dental treatment from the dentists or staffs (51.7 and 40.9%, respectively). It is important to note that HIV-subjects admitted to having fear of being discriminated by the dental staffs even if they trusted their dentists as having high morality. In conclusion, our HIV-subjects had good basic knowledge of oral health with regard to HIV infection, experienced common dental problems, and wished to have accesses to HIV-dental specialist services, if possible.