Participatory Impact Pathways Analysis (PIPA) is a practical approach to planning, monitoring and evaluation, developed for use with complex research-for-development projects. PIPA begins with a participatory workshop where stakeholders make explicit their assumptions about how their project will make an impact, and produce an 'Outcomes logic model' and an 'Impact logic model'. These two logic models provide an ex-ante framework of predictions of impact that can also be used in priority setting and ex-post impact assessment. PIPA engages stakeholders in a structured participatory process, promoting learning and providing a framework for 'action research' on processes of change. © 2010 Taylor & Francis.