Abstract. It is argued that the organization of services by local authorities should take into account both the demographic features of the usually resident population and the spatial dimension of the territory involved. Focusing on the Italian region of Tuscany, the paper seeks to identify homogeneous and spatially contiguous areas between the municipal and regional levels. Demographic indexes of usually resident population and spatial attributes of each Tuscan municipality are used as the input of a spatial clustering and regionalization model in order to obtain nareas that minimize the internal heterogeneity of the demographic structure under the constraint of spatial contiguity