Among the studies on urban services in the southern cities, few tackle the subject of gas. And yet, it has become an increasingly necessary domestic energy in these cities. In recent years, Egypt, like several other countries (Tunisia, Algeria, Turkey), has developed a new modern urban service, industrial equipment, a city gas network. This is a major reform which entails replacing a handmade distribution of gas cylinders by this network. Such reforms have radically changed the western cities since the nineteenth century. Thus, through the implementation of this project in Cairo, we study the outlines of change in urban settings, social and political, of a metropolis in urban transition. The crucial point is the social efficiency of the reform, supported by the World Bank, in a fragmented city, characterized by socio-spatial discrimination in access to services. Actually, if this reform strengthens this discrimination, the reason lies neither in the privatization of the service, nor in the model of service organization, but rather in the unchanged outlines of public management, privatized by the regime and characterized by corruption. So, this reform only means a technical modernization of the service. These results are a means to discuss the implications of the development concept in the South, an issue less technical than fundamentally political.