This article assesses whether the repatriation of civilian prisoners of war, most of whom were East Prussian deportees, from Simbirsk to Germany between April and June of 1918, was carried out according to the terms of the Treaty of Brest-Litovsk. Simbirsk, which was home to more East Prussian deportees than any other internment site in Russia, is particularly well-suited for a case study of the repatriation of civilian prisoners from Russia during World War I because the correspondence and memoirs of those who were involved in the repatriation still exist and are accessible outside Russia. The article concludes that the repatriation of civilian prisoners of war interned in Simbirsk was not carried out according to the terms of the Treaty of Brest-Litovsk—at least not according to how the treaty was interpreted by the German and Russian governments—and identifies several reasons why this was the case. This case study may have policy implications for the current war in Ukraine, which has also been characterized by the deportation of civilians from Russian-occupied territory to Russia, although on a much larger scale. If the war in Ukraine ends in a negotiated settlement between Ukraine and Russia, the repatriation of Ukrainian deportees will be an important part of that settlement. The article offers several recommendations for the Ukrainian officials who would be responsible for negotiating such a settlement to avoid chaotic evacuations similar to what happened in Simbirsk during World War I.