The Exchange of Populations’ Convention was signed on 30 January 1923 during the Lausanne Peace Conference. The agreement actually set down a compulsory exchange of populations between Greece and Turkey, which involved the Turkish and Muslim inhabitants of Greece as well as the Greek islands and the Greek and Orthodox inhabitants of the various towns in Turkey. The separation of the Greek and Turkish communities eventually led to major political, economic and social changes in both countries. In the newly emerged Turkish Republic, with the expulsion of the Greek community, Turkish leaders grasped the opportunity to reshape the political and economic structure of the country for their own benefit and that of their coreligionists who formed an alliance and funded their efforts to this end. Two Mediterranean cities, Adana and Mersin, will be taken as case studies to reflect the transformation in the political, economic and social structure of the Ottoman Empire and the Republic of Turkey during the century following 1830. The aim of this paper is to present a comprehensive analysis of the Exchange of Populations and its impact on the socio-economic reconstruction of the two Mediterranean cities.