In the age of globalization, civil society becomes a major player in global politics. We find between these players, the Transnational Network of Social Movements, Via Campesina, which is one of the most emblematic examples. This is an heterogeneous network formed by social movements composed by actors, which are kept apart by their own societies, united by a common purpose of fighting for the implementation of a new model of development based on the idea of food sovereignty which could replace the actual neoliberal model. This essay seeks to investigate the capacity of Via Campesina to influence the agricultural and development negotiations at the international level. For that purpose, we investigate its relationships with two of the main international institutions, which negotiate the agricultural matter at the international level: the FAO and the WTO. Further on, we want to demonstrate that the Via Campesina´s relevance goes beyond its relationship with state players. With this intention, we tackle the relation of mutual influence with the local organizations from witch they are built; its interaction with NGOs and research institutes and its participation in social forums. One way to get to this question is to evaluate the backgrounds, motivations and the network evolutions; we mention, moreover, its main campaigns, among which, we favor the Seeds Campaign against the transgenic agriculture.