This article examines the effect of the EU border control agency, Frontex, in its use of information. The agency organises information and analyses what is deemed to be a ‘risk’ for EU external borders. According to Barnett and Finnemore [2004 Rule for the World: International Organizations in Global Politics (Cornell University Press: New York)] such a task can be regarded as ‘a form of power’. Frontex has developed, under the supervision of the European Commission and member states, a particular process of categorising irregular migrants, in order to determine which member states’ external borders should be considered ‘high risk’. This article traces how Frontex has developed a risk analysis and how this has been used in the policy-making process. As this article demonstrates, the financial resources of the European External Borders Fund are distributed to member states based on Frontex’s risk analysis. It also discusses that Frontex is now assessing the member states’ internal borders. These cases effectively show that its assessment affects the ability of a member state to get access to EU funding and defines whether a member state is legitimately able to reinstate the border checks at its internal border. Frontex’s risk analysis is not a simple aggregation of data for operational border checks and surveillance activities, but that it should be seen as a particular form of knowledge with an important political effect.