Over the past decade, social accountability for health has coalesced into a distinct field of research and practice. Whether explicitly stated or not, changed power relations are at the heart of what social accountability practitioners seek, particularly in the context of sexual and reproductive health. Yet, evaluations of social accountability programs frequently fail to assess important power dynamics. In this commentary, we argue that we must include an examination of power in research and evaluation of social accountability in sexual and reproductive health, and suggest ways to do this. The authors are part of a community of practice on measuring social accountability and health outcomes. We share key lessons from our efforts to conduct power sensitive research using different approaches and methods.First, participatory research and evaluation approaches create space for program participants to engage actively in evaluations by defining success. Participation is also one of the key elements of feminist evaluation, which centers power relations rooted in gender. Participatory approaches can strengthen 'traditional' health evaluation approaches by ensuring that the changes assessed are meaningful to communities.Fields from outside health offer approaches that help to describe and assess changes in power dynamics. For example, realist evaluation analyses the causal processes, or mechanisms, grounded in the interactions between social, political and other structures and human agency; programs try to influence these structures and/or human agency. Process tracing requires describing the mechanisms underlying change in power dymanics in a very detailed way, promoting insight into how changes in power relationships are related to the broader program.Finally, case aggregation and comparison entail the aggregation of data from multiple cases to refine theories about when and how programs work. Case aggregation can allow for nuanced attention to context while still producing lessons that are applicable to inform programming more broadly.We hope this brief discussion encourages other researchers and evaluators to share experiences of analysing power relations as part of evaluation of social accountability interventions for sexual and reproductive health so that together, we improve methodology in this crucial area.