The UN peacekeeping operations emerged in the context of the Cold War. They were basically conceived as military interposition forces, to monitor cease-fires between parties in interstates conflicts. After the Cold War the normative changes in the international context provided for the emergence of the UN multidimensional peace operations. These operations were aimed at the resolution of intrastate conflicts, by means of the assistance on the implementation of peace agreements between the parties. With multiple functions, as well as components, the purposes of these new missions included the post-conflict reconstruction of states. The objective of this study is to examine the process of institutionalization of a framework for the UN multidimensional peace operations, including principles, norms and guidelines for the fulfillment of their tasks in the fields of human rights, civilian police and electoral assistance. The central argument here is that the current framework is the result of the interactions between the UN Secretariat and the member states. It is also the product of the impact of the normative contexts outside and within the UN structure on the identities and preferences of the actors concerning the policies of the Organization in the area in focus. The role of the UN bureaucracy in this process is emphasized in this study.