HIV testing is the gateway to biomedical means of prevention and treatment. Identifying predictors of HIV testing is important to inform future preventive interventions. Of 444 men who have sex with men without known HIV infection enrolled in a study in Hong Kong, 64% had ever been HIV-tested. Testers were generally older, better educated, had a higher monthly income, and more likely self-identified as gay. Testers often used Internet and frequented saunas for sex networking, compared with non-testers attending bars, massage centres and public toilets. HIV testing habit also varied with the profile of body image type and preferred type in sex networking. Higher acceptance of pre-exposure prophylaxis (PrEP) was observed among testers. Overall, socioeconomic status played an important role in both HIV testing and access to PrEP. Interventions targeting sex networking venues and alternative means of testing provision are needed to increase coverage of HIV testing.