Urban structures, as well as the ones that are under the direct influence of a city, can be classified by population, surface area, economic activities, dynamics and mobility. In literature and in official planning and organisation documents, various names are used: metropolitan area, functional urban area, growth pole and so on, having different definitions depending on the country or region. Polycentric development of urban settlements is one of the most pursued modern strategies in order to obtain an even economic growth at a local and metropolitan scale. In this way, several measures can be taken in order for the goals of the metropolitan area as an institution to be achieved. Among the advantages of polycentrism, we mention a more efficient land use, reduced pollution, less traffic, developing the cohesion among the territorial administrative units and strengthening the relationships among them. All of these lead to a sustainable metropolitan development, a key concept widely discussed in territorial planning. In the context of the existence of a metropolitan area as an official administrative entity to assure a coherence among its members and the context of a fast growth of the periurban area, this paper aims to evaluate the actual situation regarding the gaps, territorial inequalities and the degree of integration in Iași Metropolitan Area (IMA). Using GIS and spatial analysis methods, we are looking for the answer to several questions, such as: ”To what extent are the communes inside IMA chosen by the proximity or by the economic development criterion?”, ”What are the dimensions and activities within IMA that lead to an even development?” and ”How could a GIS-planned development lead to breaking the inequalities and help a polycentric and sustainable development happen?