- This paper examines the changing role of AIDS service organizations (ASOs) in the provision of community-based HIV services. The paper draws on a study of the development of ASOs that is based on in-depth interviews with about 250 individuals involved in the provision of HIV-related community-based services in 12 cities in Canada. Findings indicate how the broadening and increasingly complex needs confronting ASO workers are leading them to become more focused in their efforts. The paper also shows how ASOs are having to reassess their ties to other service organizations and, often, to redefine their mandate in the light of the changing needs associated with HIV. The paper explores some of the problems associated with these changes, and suggests how changing service needs require a renewed commitment on the part of ASOs to work at the level of advocacy and political change.