Description: Objective To determine the feasibility of a Community-Based Participatory Tobacco Dependence Strategy (PROMPT) in the inner city population of Ottawa (Canada). Design A feasibility mixed methods prospective cohort study following principles of community-based participatory action research. Intervention Recruited 80 people whouse drugs, followed them for 6 months while providing access to counselling, nicotine replacement therapy and peer-support in a community setting. Setting Community research office in downtown Ottawa, adjacent to low-income housing, shelter services and street-based drug consumption. Primary outcome Retention rate at 6-month follow-up. Secondary outcome Biochemically validated 7-day point prevalence smoking abstinence at 26 weeks, self-reported abstinence in the past 7 days with exhaled carbon monoxide ≤10 ppm. Results The average age of participants was 43.8 years. The 6-month follow-up rate was 42.5%. The mean number of smoking years reported was 27.3 years. The participants were 70% male, 33.7% reported less than a high-school education, 21% identified as indigenous and 43.8% reported an income between US$1000 and US$1999 per month. The baseline mean daily cigarette use was 20.5 and 9.3 cigarettes at study end, with mean reduction of 11.2 cigarettes at 6 months (P=0.0001). There was a considerable reduction in self-reported illicit substance use (18.8%), including a reduction in the opioids heroin (6.3%), fentanyl (2.6%) and Oxycontin (3.8%). The study findings also reveal psycho-socioeconomic benefits such as improved health, return to work and greater community engagement. Conclusions The PROMPT project describes socioeconomic variables associated with tobacco and polysubstance use. A programme focused on tobacco dependence, easily accessible in the community and led by community peers with lived experience is feasible to implement and has the potential to support positive life changes. PROMPT’s patient engagement model is an effective harm-reduction strategy for the growing opioid use crisis and can improve the health outcomes of marginalised at-risk populations worldwide.