There is a trend in government to establish semi-autonomous public organizations, “Agencies”, to carry out public tasks, implement policies, regulate markets and policy sectorsor deliver public services. Once an Agency is established, it is necessary to ensure proper governance. Object of this paper is to answer three Research Questions. RQ1: “Is EU Agencies governance subject to change over time”? If the answeris “Yes”, a second question (RQ2) pops up: ‘Why EU Agencies’ governance is subject to change?” Last but not least, change has to be implemented. The topic is developed in relation to the choice made by the European Union,the one-size-fits-all modelthat makes the work of controllers simple. Are we sure that such a model“is the best choice for EU Agencies’ governance?” (RQ3). If RQ1 is self-evident, more interesting are RQ2 and RQ3 because explain the nature of change (Why) and How change was introduced. In this quest, the tasks assigned to the Board of Directors and the Executive Directorare mapped against Agencies’ mission. In the case of the European Police Office, in eight years three founding acts-an international Convention, a Council decision and a Regulation - have changed the tasks of the Board of Directors and of the Executive Directorin line with the evolution of the political scenari: from intergovernmental cooperation to a policy assigned by the Lisbon Treatyto the European Union.