Cross-border integration is assumed to promote European cohesion. Yet the relationships between different forms of integration and the social and political outcomes they supposedly promote vary. In this paper, we investigate forms of cross-border integration in the Upper Rhine, comparing patterns of functional integration (socioeconomic indicators) with patterns of organizational integration (network ties between economic development organizations). Using network analysis techniques and qualitative interview data, we find that both forms of integration are driven by the presence of economic differentials between countries, but that spatial patterns of functional integration differ from those of organizational integration. We propose a typology of potential relationships between regions that explains these differing patterns of integration, and highlights how economic development actors respond to the effects of economic differentials on their regional economies. In addition, we highlight complex relationships between organizational and functional integration, institutional integration, and structural contexts.