Hong Kong, a Special Administrative Region (HKSAR) of the Peoples' Republic of China (PRC), has a low prevalence of HIV infection. This has been attributed to an extensive prevention and control program implemented by the Hong Kong government from the very beginning of the epidemic. Since the early 1990s, HIV-related surveys in Hong Kong have delineated the magnitude of the problem and identified particularly relevant cultural features that both increase and limit the risk of the transmission of HIV. Factors that may increase transmission include high rates of regional travel, cross-border mobility, and growing commercial sex industries nearby; the latter two are particularly important. Protective factors may include a later age for first sexual experience than in Western countries. More epidemiological research, and particularly intervention research, is needed in the HKSAR to identify new means to maintain the current low HIV/AIDS prevalence and to further strengthen prevention and control programs. Collaboration between government bodies, non-government organizations, and researchers is needed to assure that the best programs and policies are identified and implemented.