Aims: In most countries, cannabis use rates are highest among young people. Efforts invested in cannabis prevention programmes have had limited success. In part, this may be attributed to a dearth of meaningful discussion in classroom settings on the topic and scarcity of credible resources. Although young people want opportunities to engage in dialogue focussed on cannabis, educators often feel unprepared to facilitate such discussions. Methods: In this knowledge translation study based on recent ethnographic findings, a film was created to explore decision-making and cannabis use among young people. Accompanying curricular materials were developed to support adult facilitators in leading group discussions. Findings: The film-based resource was used in 55 sites across Canada by 48 facilitators (school staff, public health professionals and youth workers); the film was viewed by more than 2500 students. Qualitative content analysis of facilitator evaluations along with telephone interviews revealed the impact of using the innovation. Facilitators adapted the resource in a variety of classes where in-depth discussions occurred, generating critical self-reflection. Conclusions: The diffusion of this drug education innovation underscores the importance of youth engagement in prevention programmes. Prevention approaches that accommodate inclusive and balanced discussion about cannabis use can support young people in their decision-making.