In the past few years, the European Union and European and US development agencies have invested in total approximately 6 billion euros in numerous projects in the countries of the Western Balkans (Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia, and Serbia). Broken down to the population of the region, in total, over the past six years, at least EUR 2.100 were invested per capita. Mapping these projects has shown that most of them, particularly in the private sector, remain at the national level and there has so far been comparatively less financial support for interregional economic cooperation projects. At the same time, there is evidence that EU investments, as well as the quality and quantity of transport infrastructure, have a statistically significant positive effect on GDP growth in the Western Balkans. One suggestion is, therefore, maximising the use of EU financial support in the field of infrastructural projects that will eventually enable the region to make a transition from economic cooperation of separate markets towards economic integration. One aspect of that is the joint appearance of the Western Balkans countries in other markets.