This research article forms the theoretical basis of a new method for advocacy evaluation, called Narrative Assessment. Piloting the method led to a manual, also available in this library. This article proposes an approach to monitoring and evaluating advocacy that integrates theory of change and storytelling. This approach, called Narrative Assessment, addresses the feasibility of objectivity and evidence in the complex context of advocacy and proposes an evaluation methodology rooted in alternative conceptualizations of rigour and of evaluator roles. The approach centres on practical judgment and the construction and examination of stories through interaction between advocates and monitoring and evaluation specialists. The article discusses how Narrative Assessment can be useful in the evaluation of advocacy in terms of (1) monitoring and evaluation specialists’ orientation toward programmes; (2) the interpretation of outcomes; (3) the assessment of outcome relevance; (4) reflection and learning and (5) the communication of programme results. The approach builds on lessons drawn from evaluation of eight advocacy programmes in international development.