Over the last decades, Cambodia has constantly been the scene of national and international military conflicts. The cruelties peaked under the sway of the Khmer Rouge and its leader Pol Pot. Following long lasting and tough negotiations, the United Nations finally initiated a peacekeeping mission after the end of World War II. The mission aimed to enable free and fair elections in order to restore political stability and peace for Cambodia.In many respects, this United Nations mission was a milestone. No former UN endeavour can be compared with it financially, personnel-wise or regarding the scope of UNTAC. Although more than 20 years have passed since the deployment of the mission, the experiences and lessons of UNTAC are still pertinent for current peacekeeping missions of the United Nations. This diploma thesis deals with the specific aims, challenges and lessons of the United Nations mission in Cambodia.