This chapter explores a yet-untested approach for collaborative human rights impact assessment (HRIA) - defined as a joint process undertaken by project-affected people and a company, potentially with the host government or other stakeholders, to investigate, measure and respond to a business project’s human rights impacts. The approach emphasizes deep collaboration between stakeholders. This differs from company-commissioned HRIAs, which usually do not create space for project-affected people to jointly define and implement the process. This chapter explores why stakeholders might wish to undertake a collaborative HRIA, as well as factors affecting the appropriateness of the approach in specific contexts. It also provides an overview of the collaborative approach to HRIA, including discussion of participants, key steps, structure and governance, methodology, dispute resolution and funding. Finally, the chapter reflects on key challenges and opportunities relating to the local context, characteristics of the project and the people affected, and issues related to time and timing.