The purpose of this article is to outline a theoretical reflection on the production of cross-border space to capture its complexity and to analyze its structure. A conceptual framework has been developed to understand this issue. It reveals firstly that contextual factors are involved in the production of cross-border space, because they influence the territorial dynamics within it. On the other hand, two processes intervene: the bordering highlights the paradoxical relationship between the (geo)political and societal approaches of the border while cross-border integration appears as the engine of the production of the cross-border space. In order to better understand the features and functioning of the latter process, the concept has been deconstructed, highlighting four dimensions (structural, functional, institutional and ideational). The last part of this paper consists of the application of the grid analysis on the production of the cross-border space through the example of the cross-border metropolis of Lille–Kortrijk–Tournai.