The European Union next enlargement will constitute a significant qualitative change in the structure of the current Union, as the accession of the Western Balkan countries and of Turkey in particular will bring a brand new set of economic problems. It is expected that this enlargement to have a considerable effect for the new entrants, as well as for the European Union as a whole.

Considering some of the aspects raised by a new extension, this article aims to observe the trade impact of a new enlargement with the membership of the Western Balkan countries and Turkey, as this new growth is expected to have a considerable effect for the new entrants and for the European Union as a whole.

This study is based on the compare of the potential trade creation effects with the trade diversion effects resulting from the removal of trade restrictions for Western Balkan countries and Turkey and the European Union, by using the revealed comparative advantage index.

The analyze objective was to estimate the degree of trade creation and trade diversion outcome on the EU countries when Western Balkan countries and Turkey are included into the Union market.

The obtained results suggest that the export structures differ significantly among Western Balkan countries and Turkey and the European Union. Based on the revealed comparative advantage indexes, the authors would expect an intra-regional trade creation effect, but also we expect a risk for the Eastern European countries trade with European Union, especially as a result of Turkey’s accession into the European markets without any trade barriers.

As far as trade creation and trade diversion effects are concerned, they observed that Western Balkan countries and Turkey, probably, do not change the European Union position significantly because of their lower trade volume comparing with the one of the EU-27.