The metropolitan dynamics typology of the Portuguese urban system is the product of a methodology based on Geographic Information Systems (GIS). A GIS data describes six dimensions of metropolisation (population, economy, urban organisation, society and culture, networks and territorial organisation), based on a matrix of entities or indicators. Such a matrix has been subjected to treatment by neuronal networks through a Self-Organising Map (SOM). The method is robust in order to obtain a typology designated as DYMET (Metropolitan Dynamics Typology). As a result of the application of SOM’s classification algorithm ten types of areas were identified (metropolis core of Lisbon and of Porto, suburbanised area, suburbanised area in consolidation, potential metropolis centre, metropolisation area, area of urban dynamics, area of local centrality, peri-urbanised area, area with weak urban dynamics, area without urban dynamics) and compared to the typologies based on empirical studies of the Portuguese urban network developed mainly in the nineties. The identified types are described and characterised with some global dimension indicators.