This chapter looks at the methodology and practice of sector-wide impact assessment (SWIA), a methodology developed to consider sector, cumulative and project-level human rights impacts holistically. The chapter starts with outlining the methodology and discussing the rationale for undertaking a SWIA as compared to other types of methodologies used to identify, analyse and address impacts of business activities on human rights. The process of conducting a SWIA is then described, drawing on practical examples from Myanmar and Colombia. The chapter argues that SWIA can help to create a shared vision of responsible business conduct across stakeholders through facts-based analysis and dialogue. This shared vision can in turn provide the basis for actions by different stakeholders to address the adverse human rights impacts of a sector comprehensively. The chapter concludes with a discussion of challenges, lessons learned and pathways forward for the future development and application of this methodology.