The need for broader consideration of sustainability outcomes has been leading the discourse in the field of impact assessment during the twenty-first century. The ability of qualitative methods from the social sciences are being proposed as having the potential to integrate different types of knowledge in order to identify, explore, and assess impact pathways that address more social sustainability concerns around development such as values, culture, well-being, psychosocial impacts, rights, and cumulative effects. The purpose of this research was to explore how qualitative methods in the Canadian assessment context can contribute to this next generation of impact assessment. As such, my thesis undertakes to identify examples of qualitative methods being used in Canada and to explore how some of them are being applied in a case study context. It also identifies broad challenges and barriers to using qualitative methods and explores how these might be addressed using good practice. I employed semi-structured interviews with practitioners and document review from three proposed projects, the Teck Frontier Mine, BC Hydro’s Site C Clean Energy Project, and Benga’s Grassy Mountain Mine. I found that key qualitative methods being used in the Canadian context included interviews and focus groups. I found that there were important design considerations in IA for using qualitative methods, particularly in community-based research contexts, such as sampling, methods protocols, interpreting human experiences reflected in data, and qualitative data analysis. Key institutional challenges that limited the application of qualitative methods into assessment included formal institutional processes that struggled with integrating qualitative data, guidance on implementing, decision-making using qualitative data as evidence, and other logistical and political challenges. In conclusion, careful design, good guidance, and collaborative process are key to grounding qualitative methods to assessment and decision-making outcomes.