A thematic network is a group of local agents of the European Union and Latin America committed to a common theme of urban problems. Each Thematic network has a coordinating city, 50 to 200 members, and it prepares Common Projects to be submitted by the coordinating city to the European Community for approval.

The Common Projects emphasize the local agent partnerships, enabling the effective establishment of solid and last-longing relations, leading to identification of solutions to common problems and their concrete applications. The subjects are related to Thematic Network issues enabling development of specific aspects of the Network's general problems. Taking part in common projects involves low costs for the participating cities and makes it possible to have Access to information and several contacts.