The question of migration within the European Union, as well as between its member and non-members states, has become recently an important issue. Among the EU and OECD countries, Poland is not a major recipient of immigrants. However, in recent years one can observe a growing number of both permanent and temporary immigrants, most of whom are Ukrainian citizens, whose main departure motive is work. The main purpose of the paper is to conduct a comparison of the migration patterns for Poland and Ukraine, as well as survey the mutual causation forces that determine the structure of the Ukraine-Poland migration corridor. The paper consists of three parts. It starts with an introduction followed, by theoretical backgrounds of migration, outlining its main types and models. The next parts highlight the volume, directions and structure of migration flows for Ukraine and Poland. The evolution of the Ukraine-Poland migration channel and its mutual effect on the economies of both countries is highlighted in the final part.