<p>Several factors limit the adoption of harm reduction in cannabis use (HR-c). A knowledge translation (KT) process can help optimize its adoption. This study aims to: (1) identify the attitudes toward HR-c of health and social services (HSS) practitioners working among young people in Quebec; and (2) develop a KT plan to enhance its adoption. Two conceptual frameworks guided the study: the Knowledge-to-Action model and the Consolidated Framework for Implementation Research. Managers and practitioners working among young people in difficulty in Quebec were recruited. Mixed methods tools were used, involving consultations (<i>N</i> = 14) and questionnaires (<i>N</i> = 167). Qualitative data underwent thematic analysis, while descriptive and inferential statistics were executed to analyze quantitative data. Participants presented positive attitudes toward HR-c (<i>M</i> = 44.79), negative attitudes toward abstinence-based treatments (<i>M</i> = 9.68), and moderate perceived levels of training in HR-c (<i>M</i> = 12.3). Their needs and contextual factors that might influence HR-c adoption were identified. Based on these findings, a KT plan was developed to optimize HR-c adoption by HSS practitioners. Despite some negative factors impacting its applicability, HR-c is generally accepted and implemented by practitioners. This study represents the pre-implementation phase of the KT plan, which will then guide the effective implementation of a KT process for HR-c adoption.</p>