The purpose of the article is to provide political analysis of European Groupings of Territorial Cooperation (EGTC), which are being currently established on the Polish-Slovak borderland. First, the author presents the essence and legal basis of this new instrument of the European Union, and describes the origin of the first EGTCs. Second, in the main body of the text, he discusses two Polish-Slovak EGTCs, i.e. Tatra and TRITIA, focusing in particular on their documents of incorporation, internal organization and the planned scope of activities. The article is supplemented with a comparative analysis of previously active euroregions. In the summary, the author offers some conclusions and recommendations regarding further formalization of Polish-Slovak trans-frontier cooperation.