The care and rehabilitation of displaced, orphaned or lost children after World War II became a significant challenge for the international humanitarian organizations, as well as for the military governments in the occupied territories. This dissertation explores the policies and practices that the welfare authorities and officers of the United Nations Relief and Rehabilitation Administration (UNRRA) and International Refugee Organization (IRO), as well as American military officers in the US zone of Germany, formulated regarding the relief and resettlement of unaccompanied displaced children of Ukrainian origin between 1945 and 1952. From the autumn of 1945 onwards, the humanitarian officers with the approval of American officials in the US zone of Germany started to withhold Ukrainian children who originally came from the eastern Polish territories that were annexed by the Soviet Union from repatriation. The US military authorities declared that they did not recognize these children as Soviet citizens and instructed the welfare officers to consider them as nationals without governmental representation. As a result, the conflict over these children with the Soviet authorities, who were eager to repatriate them was inevitable. This dissertation explores how this geopolitical dispute shaped the policies of resettlement, care and welfare provision related to displaced children. By analyzing how the welfare officers and US military officials debated the national belonging and future destiny of these children, this study demonstrates how their decisions and activities in relation to Ukrainian children were founded on a humanitarian and political setting, which was formed by a pre-Cold War discourse. The examination of the IRO welfare officers' work with these children on the ground showed that repatriation to the Soviet Union was no longer considered to be in the best interests of Polish-Ukrainian children, while emigration and settlement in Germany was. This led the study to make a striking observation on how the IRO's welfare workers began to reconsider the future plans for the unaccompanied children who were living in German foster families. Namely, that from 1948, not long after the war had ended, welfare officers began to consider that allowing children to be adopted into German families would be in their best interests. Such opinions were voiced in spite of the Nazi’s Germanization program still being fresh in peoples’ memories, as well as more general fears that German society would hold a negative attitude towards foreign children. Finally, this case study provides a closer look at the complex relationships between the military and welfare authorities and officers that ranged from the disagreements about approaches to a child's resettlement to their joint work in the issues related to Ukrainian children.