The purpose of this study was to provide both a population estimate and a socio-economic and health profile of gay and bisexual men living with HIV/AIDS in a large Canadian urban centre. A random telephone survey was used to determine the number of men in the study area over the age of 20 identifying as gay or bisexual and to characterize their health and socio-economic status. Out of a total of 1,176 completed interviews, 300 males described themselves as gay or bisexual. Projecting this figure on recent census data we estimated the number of men identifying as gay or bisexual in this region of downtown Vancouver, BC, at 5,100. Among these men we found an HIV prevalence rate of 16%, with those who reported a positive serostatus being less likely to be employed full time and more likely to earn less than $20,000 per year. In terms of clinical characteristics, HIV-positive men had a median CD4 cell count of 397 cells/mm(3) and a median viral load of less than 500 copies/ml. Eighty-three per cent of the HIV-positive respondents were on antiretroviral therapy and the median number of drugs taken by these men was three. In summary, random surveys of populations affected by this epidemic are important for policy makers, clinicians and persons caring for those with HIV/AIDS as they paint a clearer picture of who is being affected and help to identify areas where increased services are needed.