Background: The Quebec Government published Canada's first breastfeeding policy in 2001 with the goal to increase breastfeeding rates in the province.

Objective: To ultimately contribute to more informed policy decision-making, this investigation aimed to identify key stakeholders and understand events and processes that contributed to the establishment of this policy.

Methods: Building from the neo-institutional theory, this was a retrospective case study. Interviews with key informants were conducted, and several texts were compiled. Hybrid thematic analysis was used to analyze text transcribed verbatim from interviews. Resulting themes, summary of archival material and temporal bracketing were adopted to elaborate a historical narrative of the development of the policy.

Results: The emergence, development and initial implementation of the Quebec breastfeeding policy phases were traced from 1977 to 2009. The policy was triggered by a grassroots health professional movement that advocated for years for a cultural change toward breastfeeding in Quebec. Once Quebec's Ministry of Health finally accepted dialogue, institutional actors cooperated to formulate the policy. However, conflicts arose because of the Ministry's increasingly centralized mechanisms of governance. By 2009, discontent was so pervasive that several health professionals and other breastfeeding actors created an independent organization to further support breastfeeding, out of the Ministry's scope of control.

Conclusion: Collaboration in this domain was possible when shared decision-making was accepted, but conflict emerged when the institutional actor with formal authority re-adopted traditional top-down modes of action.