HIV testing is promoted to the public as a tool for HIV prevention in many countries. However, the patterns and determinants of HIV antibody testing among the Chinese people are unknown. To describe the prevalence and determinants of HIV antibody testing amongst the Hong Kong Chinese a cross-sectional anonymous survey was carried out among 1,027 subjects from different population groups (airport travellers, business sector workers, service sector workers, university staff, and STD clinic attendees). Subjects were categorized into either 'STD population' (respondents from STD clinics) versus 'all others' (respondents from other settings) groups. Forty-five percent of the respondents reported ever having had a test for HIV antibody. 'STD population' group members were almost three times more likely to have had an HIV test than were 'all others' group members (77% vs 20%). After adjustments, 'STD population' group members who reported having tested for HIV were more often aged 45 years or older, alcohol drinkers, with high self-efficacy scores, and inconsistent condom users; members in the 'all others' group, more often had had sex with strangers, drank alcohol, and favoured having multiple sex partners. Awareness among the public about the risk behaviours for HIV should be enhanced and efforts should be made to reduce high-risk behaviours among those tested by emphasizing the importance of maintaining safer sex behaviour and having follow-up tests during post-test counselling.