The majority of women serving short-term sentences in provincial prisons in Canada are incarcerated for illegal activities involving alcohol and substance use. Although there is a wealth of research on substance use among those serving sentences within the federal prison system, little of that literature addresses the needs and experiences of women prisoners. Additionally, very scant research exists on the experience of women incarcerated in the provincial system for crimes related to drug and alcohol use. The purpose of this article is to present the results of a Canadian participatory research project conducted in a minimum-medium security provincial prison. In conducting this project, our objectives were to understand incarcerated women's perspectives on reasons for their substance use, why they continued to use, the consequences of their use, and their suggestions for change. The data were collected and analyzed by the collaborative efforts of both the peer researchers who were incarcerated women at the time of the research and university-based researchers. Upon release, several women continued on the project as co-researchers and co-authors of this paper. We present the results of a "drug of choice" survey and the qualitative responses to open-ended questions concerning prisoners' use of drugs and alcohol. (Contains 2 tables.)