The present study examined the prevalence and factors that were associated with HIV testing behaviour among the MSM population, the male clients of female sex workers (FSW) population and the lower-risk male population in Hong Kong. Results revealed that out of the 2,074 male respondents surveyed, 7.3% indicated that they had been tested for HIV antibody in the past six months. The prevalence of HIV antibody testing among those who had ever had sex with the same sex (MSM) and those who had visited one or more female sex workers in the past six months was 15.5% and 16.1%, respectively. Private clinics were found to be the most popular venue for testing. Factors associated with HIV testing included whether the respondent had had sexual intercourse with FSWs in the past six months, MSM behaviour and number of female sex partners in the past six months. Possible reasons for the low prevalence of HIV antibody testing in Hong Kong and implications of the findings are discussed.