In Portugal, the design and the implementation of models of primary care teams has a history of 30 years. The evolution observed is from individual medical work, in Health Centres, supported on an ad hoc basis by other health professionals, to health centres integrating a diversity of formal working groups, including primary care/family health teams called "Family Health Units" (FHU). This evolution included the creation and gradual affirmation of the speciality of family medicine and the experimentation with different models of primary health care provision: voluntary primary care health teams without financial incentives (Alfa project), voluntary primary care health teams with a performance-related-remuneration system and the current phase of scaling up FHU. The process described here illustrates how a group of physicians has established a non-formal strategy of reform throughout 30 years. This strategy involves mobilization policies and the development of field experiences by individual leaders, groups and organizations.