This article analyses the socio-economic impact of the Naples business centre (CDN), a large redevelopment project for a complex of offices and residences built in the core of the metropolitan area of Naples over the last two decades. Naples, one of the major cities in the underdeveloped regions of the south of Italy, presents specific processes of social exclusion and polarization. Currently the city faces the restructuring of the local economic system as well as the problems generated by its historical path of development. The article begins with a discussion of the main dimensions of social, economic and political exclusion. In this context, it discusses the two fundamental sources of exclusion in Naples: labour problems (unemployment, informal work and the impact of a clientelistic welfare policy) and the lack of a ruling framework of legality (new links between organized crime and the political system, widespread corruption, money-laundering). It then describes and evaluates the city’s urban policy and strategy in the face of these problems over the last three decades. The decision-making and implementation processes of the CDN are described and an account given of the dynamics of the public-private partnership involved in its development. The final section evaluates the physical, economic and social impact of the CDN project and demonstrates that it has not only failed to address the principal problems of the city but has actually aggravated them.