In this paper we deal with cross-border flows of people within the Euroregion Galicia-North of Portugal, paying particular attention to those led by workers. Based on data for daily mobility between the places of residence and work (commuters), it can be defined, within this territory, the so-called Polycentric Urban Regions (PUR) of Vigo and Porto. These regions should constitute significant referents of cross-border mobility, whose importance we begin to realize by estimating the movement of passengers across border crossings linking the south of Galicia and the north of Portugal. In this context, given the non-existence of official statistics, the reports prepared by the Eures Galicia/Região Norte office provide relevant information about the flow of cross-border workers in the area, which we have complemented by conducting two surveys directed, respectively, to involved workers and...