To recognize elements that facilitated or hindered the PlanificaSUS implementation stages.A multiple case study was carried out in four pre-selected health regions in Brazil-Belo Jardim (PE), Fronteira Oeste (RS), Sul-Mato-Grossense (MT) and Valença (BA) using systemic arterial hypertension and maternal and child care as tracer conditions. Participant observation (in regional interagency commissions) and in-depth interviews with key informants from state and municipal management and primary health care and specialized outpatient care service professionals within the project were carried out in these four regions. Analysis was built according to political, technical-operational, and contextual dimensions.The political dimension evinced that the regions found the project an opportunity to articulate states and municipalities and an important political bet to build networks and lines of care but that there remained much to be faced in the disputes related to building the Unified Health System (SUS). In the technical operational dimension, it is important to consider that primary health care stimulated a culture of local planning and favored traditional tools to organize and improve it, such as organizing registrations, agendas, and demands. However, centralized training and planning-inducing processes fail to always respond to local needs and can produce barriers to implementation.It is worth considering the central and regional role of state managers in the commitment related to the project and the effect of mobilizing primary health care and expanding its power. There remains much to be faced in the disputes at stake in bullring SUS.