This study aims to examine the Southeastern Anatolia Project in Turkey, which contains irrigation, energy and drinking water development schemes. The project is the biggest regional development effort ever undertaken by Turkish Government and has influenced the sustainable economic and human development targets. With the completion of each step of the project, it has been expected that there have been many important economic and social changes in Turkish regions, especially the southeast part of Turkey (called as "Southeastern Anatolia Region") and its surrounding areas. The project also interests in both Turkey and its related regions and sustainability is a major issue of concern. Following a brief introduction of the project, the paper examines the type of recent social-economic changes in the region and Turkey in terms of sustainable development components. Under the light of our investigations from different perspectives, it is observed that GAP region with its development project is very far from expectations in the point of sustainability