Since the 1990s, many international institutions have gotten involved in the “fight against cor- ruption” and sought to harmonise national legislations. While a number of international con- ventions against corruption have been adopted they rely on governments’ political will to com- ply, especially in the Global North. In the absence of coercive power, international institutions have used knowledge production and the rhetoric of evidence-based policy-making to influence domestic policy-making. This paper is interested in international institutions’ use of knowledge and evidence to set the anti-corruption agenda. It questions and deconstruct what they present as evidence, showing that the meaning of the term has evolved overtime. Based on document analysis and interviews with international civil servants and NGO employees, this paper firstly comes back on the value attributed to knowledge in this policy field. It then presents what in- ternational institutions meant by evidence since the emergence of the anti-corruption agenda in the 1990s. Lastly, it critically discusses the use of knowledge and evidence, the function it plays and its effects on anti-corruption policy-making.