Collective action within territorial organizations is complex. Initiatives often collapse from a lack of understanding of relational dynamics and logics of action. This article proposes a relational approach to study the collective action process within a producer association of a Localized Agrifood System (LAS). We conducted the research within the APROCAMPOS association, located in the Serrano cheese LAS, which involves producer families, extension agents, inspection veterinarians and secretaries of agriculture. We first conducted a social network analysis of advice seeking within the association, through sociometric interviews with the producer members. Second, an analysis of territorial proximity, conducted through semi-structured interviews with the association participants, was combined with the social network analysis. Results showed that extension agents are in a very central position in the advice network. They follow a classical top down model of knowledge diffusion. The president of the association plays a key brokerage role, essential for the network cohesion and information flow. Second, the analyses revealed a lack of trust and reciprocity among producers, leading to a low level of interaction and collective action, which can, however, be improved by the combination of geographical and organized proximities. In sum, the top-down model leads to low levels of initiative and participation among the producers in collective action. Local knowledge needs to be integrated in a more participatory governance frame to build common projects of cheese valorization. Nonetheless, institutional arrangements appear instrumental to define political orientation that favors cooperation and meets the quality of the Serrano cheese and promotes the development of the territory as a whole.