Metropolitan areas in many OECD countries are fragmented into various territorial units, which do not correspond to the larger geography of economic and social problems. While the ensuing mismatch is not a new phenomenon, increasingly, fragmentation appears as one of the root causes of metropolitan dysfunctions, such as internal fiscal disparities, urban sprawl, and spatial polarisation, which in turn constitute an obstacle for competitiveness. This review examines the case of the metropolitan region of Montreal which has undergone one of the most radical institutional reforms in OECD countries. On the one hand, the amalgamations of municipalities led to the creation of the two new cities of Montreal and Longueuil. On the other hand, a new metropolitan body was set up to cover the whole functional and economic area — the Montreal Metropolitan Community (CMM). These institutional reforms provide a valuable opportunity to meet the challenges of Montreal's competitiveness. The new governance framework needs however to be consolidated, especially with regards to clarification of competencies and fiscal responsibilities and resources. Streamlining institutional structures and fiscal resources will not be enough. Implementing and not simply elaborating a comprehensive economic strategy for the whole metropolitan region will be the main challenge for Montreal in the following years.