This article analyses the process of spatial integration in ten European cross-border metropolitan regions by comparing three indicators, relating to flows of cross-border commuters, differentials of gross domestic product per capita and residents' citizenship. Our results allow, firstly, confirmation of the hypothesis that the greater the economic disparities, the greater the level of interactions measured by cross-border commuting. Our work also allows confirmation of the hypothesis that strong economic interactions have an impact on the cross-border integration of communities, measured by the proportion of residents based on the other side of the border. Finally, this article leads to a typology based on three models of cross-border integration being proposed: by specialization, by polarization and by osmosis.