Background and Objectives: African, Caribbean and other Black (ACB) persons account for an increasing proportion of new HIV cases in Canada, and are 12.6 times more likely to acquire HIV than the rest of Canada’s population. Few studies have fully acknowledged the ethnic, religious and socioeconomic diversity in ACB communities. Also, studies have rarely considered the social determinants of health and broader context in which ACB persons live and access health services, and how these may potentially impact HIV vulnerability. This lack of information negatively impacts HIV prevention and care efforts. The Black, African and Caribbean Canadian Health (BLACCH) Study was designed to address these issues. It is a community-based research project looking at health and HIV in London and Middlesex County’s ACB communities. The study’s main purpose is to improve health promotion and HIV prevention programming. Methods: The BLACCH Study is a mixed-methods study consisting of semi-structured interviews followed by a self-administered survey. Thirty interviews were conducted: eight with service providers and twenty-two with community members. Purposive sampling ensured that participants represented a cross-section of local ACB communities. Interview topics included: ethnicity; migration; HIV-related beliefs, behaviours, knowledge, experiences, stigma and services; social networks; gender; socio-economic status and housing. Interviews were transcribed and in-depth content and grounded theory analyses are being performed. Preliminary analysis highlighted themes that were used to create the self-administered survey, which will be completed in 2010-2011 by 400 ACB people who reside in London and Middlesex County. The survey covers: demographics; education, income and employment; health behaviours; sexual and reproductive health; health screening and testing, including HIV testing; and HIV service use and needs. Results: Once data collection is complete, appropriate analyses will be performed to produce the following: 1) qualitative paper about interview findings; 2) mixed-methods descriptive paper about the distribution of HIV-related behaviours in ACB communities; 3) analysis comparing ACB people with different immigration profiles; 4) periodic bulletins about topics of interest to the community; 5) report covering interview and survey results; needs assessment for the AIDS Committee of London; and 6) mixed-methods papers examining the relationships between social position and HIV testing and condom use. Other analyses may be performed. Conclusions: The BLACCH Study will provide information useful for designing and implementing culturally appropriate health promotion and HIV prevention and care programs for ACB communities, especially those outside of more well-resourced urban centres. It will also provide information that can guide future research.