Those who work in support of peacebuilding and development initiatives are acutely aware that conflict-affected environments are volatile, unpredictable and fast-changing. In light of this reality, evaluation and research in the service of peacebuilding and development is a complex enterprise. Theories of change and assumptions about how peace and development work are often unarticulated or untested. While much work continues to be done on the theories, methodologies and praxis of peacebuilding, we suggest that the international aid community, researchers and practitioners need to think more deeply and systematically about the role of evaluation in increasing the efficacy of projects and programmes in violently divided societies (VDS).