The territorialization of Primary Health Care is an important social and political process for the implementation of the constitutional principles of the Unified Health System (SUS) in Brazil. The SUS is essentially a nationwide care project, organized into regionalized care networks, with its command center in Primary Health Care (PHC). For this reason, the territorialization reflects the desired model of care that is proposed in Brazil. However, even though almost thirty years have elapsed since the constitutional edict, this nationwide care project has not yet been fully implemented. The scope of this text is to reflect on the political and ideological processes of the territorialization of PHC of the SUS in Brazil and put forward some reasons that explain the difficulties of implementing this model of nationwide care. Enormous difficulties were observed in the unification of the Brazilian care model, while financial constraints worked against the strategic discourse surrounding Family Health, and recent regulations disrupted territorialized forms of work and can broaden the fragmentation of PHC in the country.