With the development of oil exploration and production around the Arabo-Persian Gulf from the end of World-War II, the towns linked with this activity have experienced a rapid growth, leading to the significant changes in pre-existed urban hierarchy. This article aims to describe and analyse the process of growth of all the cities and towns located on the two sides of the Gulf. During the last few years, the urban growth appears to be linked with new urban policies using oil revenues for building a post-oil economy. Divided between rich social groups constituted by local families and highly qualified migrants, often North-Americans on one side and on the other side poor workers, mainly Asians, far from their family and on temporary contracts along with various social groups of new migrants. The present analysis pinpoints the importance of a large and hierarchized middle class as well as a large popular class in the social fabrics, which determine local social life as well as consumption pattern. It demonstrates the social complexity of the society in large urban agglomerations of the Gulf countries, which are getting strongly integrated with the globalization process and benefitted by large investments from the states and international companies. It also shows how the middle and small towns are greatly marginalised in this lopsided development process.