BACKGROUND: African, Caribbean and other Black (ACB) people are a priority group for HIV prevention in Canada, but little is known about the epidemiology of HIV risk in this population. This paper helps fill the knowledge gap by: presenting service providers' and ACB people's perceptions about HIV risk in ACB populations; describing the distribution of HIV risk behaviours among ACB people according to markers of social status and position; and comparing results from these two analyses. METHODS: The Black, African and Caribbean Canadian Health (BLACCH) Study is a mixed methods study that used semi-structured interviews and a cross-sectional quantitative questionnaire to collect information about HIV and health from 188 ACB people in London, Ontario, Canada. Qualitative content analysis was used to identify interview themes, and weighted bivariate statistical analyses were performed on the quantitative data. Behaviours related to HIV risk were stratified by sex, poverty status, immigration experience and employment status. RESULTS: Community members perceived that they were at low risk for HIV and mainly focused on sexual risks. They called for more information about HIV in Canada and culturally appropriate HIV services. Service providers cited marital infidelity and cultural and religious attitudes about condoms as barriers to women protecting themselves. They mentioned cultural norms, beliefs about masculinity and underrepresentation of heterosexual ACB men at AIDS service organizations as barriers to men protecting themselves. There were few statistically significant differences in risk behaviours reported by men and women. Those living in poverty were more likely to abstain from sex (p = 0.006) and use condoms (p = 0.027) in the past year. Those living in Canada longer reported higher prevalences of forced sex (p < 0.001), mixing alcohol or drugs with sex (p = 0.001) and past STI diagnoses (p = 0.032). Stable employment was associated with higher prevalences of not using condoms in the past year (p = 0.005) and past STI diagnoses (p = 0.018). CONCLUSIONS: The results show that perceptions about ACB people's HIV risk differ from actual risk, and those with higher social standing might be at greater risk. Furthermore, the social determinants of health are important factors in the epidemiology of HIV among ACB people.