The literature on evidence-based action in humanitarian crises commonly focuses on how inter-and non-governmental organisations can produce better knowledge and how this can be translated into improved programming. Yet, there is little recorded experience of, or concern about, how the beneficiaries of humanitarian relief can produce and use knowledge of their predicament. This paper is based on a case study of how the Liga de Mujeres Desplazadas, an internally displaced women's organisation in northern Colombia, employs proactively research-generated data to advance its own agenda in its interactions with donor bodies and the government. The paper finds that beneficiaries of humanitarian aid can, and do, use participatory research to advance their own ends in the legal and political spaces created around humanitarian crisis. However, their agency is limited by poverty, violence, and local balances of power. The paper concludes that beneficiaries' priorities in the production of data about humanitarian crises warrant further study.