In this article the authors examined relevant experience of evaluating the effectiveness of economic integration using the example of the European Union as the most advanced integration association in the world nowadays. The article contains the analysis of the indices for integration measurement proposed by the supranational structures of the EU – the European Commission and the European Central Bank. The authors studied in detail two examples of approaches to assessing the effectiveness of integration within the EU by foreign researchers, which are based on an expanded theoretical and empirical base. The authors of the article highlight that besides the experience studied in the text, scientific publications also contain calculations of the old and new EU members integration level (Central and Eastern European countries), as well as integration and disintegration processes within the EU. Finally, the authors concluded that despite the methods adopted in the European Union for assessing the degree of its integration, this issue remains in the focus of attention of the European scientific community. Furthermore, the methodology for assessing the effectiveness of economic integration within the EU allows its leadership to timely adjust the development strategies of the integration association, which is strongly important in modern conditions. A question of integration is especially acute in the context of the systemic crisis in all EU countries, one of the main causes of which is the anti-Russian sanction policy.