The thesis focuses on the activities of the United Nations in Iraq. The thesis as such aims to analyse efficiency of the UN efforts in Iraq, with emphasis on the period after the war in 2003. The framework of the analysis is the concept of peace-building and its phases. In the first part, the thesis defines the term peace-building and its phases. In the second part the function of the UN in the country is analysed based on, among others, the project reports of the multilateral funds created to reconstruct Iraq. The third part focuses on the empirical research and it gives the theoretical knowledge into contrast with the opinions of the Iraqis themselves obtained through an inquiry.