Health-care providers are powerful figures in society. An informed service user may be able to identify regulatory non-compliance and abuses by these actors, but reporting them is not a mere administrative procedure. It is an act that stirs existing power relations and social hierarchies. This article argues that the essence of an accountability intervention is the process through which service users collect and analyse evidence that is then used to confront power at different governance levels. The response from authorities is assessed and strategies adjusted accordingly in adaptive cycles of accountability action. Based on ten years’ experience supporting indigenous citizen-led accountability action in Guatemala, the authors describe how their approach evolved from an emphasis on technical components to a politically informed approach with interdisciplinary collaboration and explicit engagement with power. This article summarises lessons learned and their relevance for organisations working in health accountability in highly unequal settings.