Understanding the cost associated with climate change adaptation interventions in agriculture is important for mobilizing institutional support and providing timely resources to improve resilience and adaptive capacities. Top-down national estimates of adaptation costs carry a risk of mismatching the availability of funds with what is actually required on the ground. Participatory Social Return on Investment (PSROI) seeks to provide a pragmatic, local-level planning and costing framework suitable for replication by government and civil society organizations. The ‘PSROI Framework’ is designed around a participatory workshop for prioritizing and planning community-based adaptation (CBA) strategies, followed by an analysis of the economic, social and environmental impacts of the priority measures using a novel cost-benefit analysis framework. This working paper seeks to outline the theoretical and methodological foundations of the PSROI framework, provide case-study results from each pilot study, and assess the strengths and weaknesses of the framework according to its robustness, effectiveness and scalability.