Between 2012 and 2014, the establishment of the National Women’s Forum was the subject of considerable controversy in Burundi, pitting women’s associations against the country’s ruling party. UN Women, which was one of the main donors of the Forum, was taken to task. This case study addresses the issue of the participation of international organisations in the (de)politicisation of women’s representation in a country that has experienced armed conflict. Against the hypothesis of a single depoliticisation, I show, by mobilising the notion of a third party with varying roles, that the actions of the UN agency are more equivocal. Indeed, UN Women first stood as a structuring third party in the conflict relating to this issue, reactivating a long-standing dispute between political institutions and women’s associations; then it served as a neutral third party, seeking to neutralise antagonisms by mobilising universal norms; finally, it acted as an excluded third party, when – unrecognised as a mediator – it reopened a space for debates on the rights and duties of the state, civil society, and the international community in representing women and defending their claims.