Metropolitan areas are based on agglomerations, which include the built-up area and the commuter belt around a city. A sustainable and inclusive development of the economic potential as well as the well-being of people living there may be developed more efficiently by taking into account the metropolitan area as a whole. Given the growing role of cities and metropolitan areas in governance this topic is high on the policy agenda of the European Commission. However, there are major policy issues in the spatial development of cities and metropolitan areas, like urban sprawl, that affect the latter’s ability to meet the goals of sustainable and inclusive growth. Policy makers in cities often have limited capacity to address these challenges, due to the de facto (and sometimes de jure) existence of functional urban areas (FUAs), defining cities and their commuting zones. These FUAs extend beyond formal administrative boundaries. Therefore, metropolitan areas often suffer from fragmented policy making. Hence, the metropolitan dimension gives new and challenging aspects to the question of how to address policy issues, since dialogue and commitment to joint policies has to be achieved by the core city and often many neighboring municipalities as well as directly elected local and regional authorities. City to city cooperation as well as multilevel cooperation are crucial points to be taken into account in this respect. Furthermore, different planning frameworks need to be considered, which in most cases are not specifically designed to strengthen inter municipal and multilevel cooperation. New governance approaches, though, are promising to ease the potentially unfavourable effects of fragmentation of different municipalities and other public authorities within metropolitan areas. Even if the roles that metropolitan areas can play for territorial development are increasingly recognised in Europe, there is still no unified typology providing policy makers with a better representation and understanding of the metropolisation of society. The latter would be of relevance for embedding metropolitan development in local and regional development discourses and strategies. Emerging local and regional development strategies across Europe address some of the metropolitan areas' challenges. Nevertheless, many places lack the policy tools and governance approaches for metropolitan planning and spatial management at metropolitan level. More specifically, some countries and cities lack formal powers for planning at the metropolitan area level, especially in Central-Eastern Europe and in federal systems. A number of other countries, though, such as France, The Netherlands, Italy and the Nordic countries, have legal frameworks, or even requirements, for spatial planning at a metropolitan level. However, even if there is a legal framework it might be the case that the territory fixed for cooperation does not cover the whole FUA. Moreover, the frameworks vary with wide differences in the level of experience, practice, institutionalization and resources, and therefore have varying measures of success. With the continuous urban sprawl in Europe and merging of urban zones within metropolitan areas, it is of key importance to assess the role of spatial planning policy and urban governance processes at metropolitan level. Spatial planning policy is one of the three main topics of cooperation in metropolitan areas across Europe. Being cross-sectoral, coordinating and integrating, metropolitan spatial policy can play a significant role in promoting sustainable and inclusive growth.