One of the three key spatial development objectives contained within the European Spatial Development Perspective (CEE, 1999) seeks the ëdevelopment of a polycentric and balanced urban system and strengthening of the partnership between urban and rural areasí (p.19) in order to achieve regionally balanced development. Recent evidence arising from on-going work addressing the territorial and functional characteristics of Spainís seven principal metropolitan areas (Barcelona, Madrid, Malaga, Seville, Valencia, Bilbao and Saragossa) within the context of the south-west European urban system, indicates significant differences in the extent to which patterns of polycentric regional development can be identified. For example with regard to labour markets and origin-destination travel flows, it is possible to detect a certain degree of polycentrism in the case of Barcelonaís metropolitan area, and a similar tendency, albeit to a lesser extent, in the case of Bilbao. By contrast, in the cases of Madrid, Malaga, Seville and Valencia, what can be observed is clearly defined centralism concentrated upon the capital city of each of these areas. This paper addresses the role of the capital cities within these seven Spanish metropolitan regions. Furthermore, it questions the extent to which there is a need for change and questions how spatial planning measures might contribute to a more balanced urban metropolitan system in Spain, taking into consideration local ëstrategic planningí objectives and European spatial development policy.