The aim of this article is the comprehensive analysis of possible benefits and disadvantages of Turkey’s European Union membership from the point of view of both of the sides of the accession process, and the attempt to predict the probable consequences of two political scenarios: accession of Turkey to the EU which is equivalent to being a full member with the same rights as remaining 27 countries, or the fiasco of Turkey’s accession process to the UE. The first part of this article contains the analysis of economic, political and sociocultural benefits that both of the sides will gain and the balance of the costs that each side will have to bear. The analysis that is being carried out in the second part of this article is concerned with possible consequences of ‘worst and best scenario’ fulfillment. However, as it is being shown in this part of article, between two mentioned above extremes there is one more possible way of progress of events: heavily supported by the chancellor of the Federal Republic of Germany Angela Merkel ‘privileged partnership’ for Turkey instead of full EU membership. How it has been repeatedly said by Turkish political leaders, none form of partnership should be even considered because offers of cooperation different from full EU membership are insult to Turkey. However, taking into consideration the fact that EU is still being affected by economic and political crisis, it may have not possibility to offer Turkey anything more than remaining the ‘status quo’. Possible results of this progress of events like Turkey’s turn to the Islamic neighbouring countries and European Union’s loss of a chance of attaching great importance to global geopolitics, are also taken into consideration.