In recent years, due to the growing supply of organic production, the economic performances and the competitive advantages of the farms, have become more dependent on network organisations in the supply chains. This evolution equires methodological approaches able to capture all the variables involved in the generating value processes. The network dimension of the supply chain has become a key element, and enables us to understand better the competitive performances of firms. The relationships of firms, among intangible assets, are recently considered one of the main sources of profit. So the relational capital forms the essence of the value of the firm and it is advantages on the whole coming out by occupying a specific position (role) in the network of social relationships, the social network (Costabile, 2001). The goods present in a context are not enough to explain the wealth of a firm or a supply chain or a sector, so it is necessary to understand the nature of exchanges and how do they work trough the network. For these reasons our study compares supply chains of organic olive oil in Italy and in Spain using the Social Network Analysis. The data was collected by survey in two areas: the Sierra de Segura (Andalucia, Spain) and the province of Bari (Puglia, Italy). By the results of our study we can assert that the Sierra de Segura shows a simple network which allows, trough a cooperative organisation, to generate value for the farms. On the other hand, in the province of Bari the network organisation is quite disperse, denoting a luck of organisation which bring to a low level in competitiveness of the whole supply chain. At the same time, firms with a good economic results have also a central position in the network.