The main research question addressed in this paper concerns the way entrepreneurs’ social networks affect the opportunity identification and the access and mobilization of resources in a science-based field – biotechnology - facilitating the founding of new firms. For this purpose we adopted an analytical framework combining contributions from the technological entrepreneurship and the social network literature and, on this basis, we proposed: i) that entrepreneurs social networks, both those associated with their academic and professional trajectories and those intentionally build already having the firm as a goal, are critical to access the wide range of resources necessary to create a new firm in this type of field; ii) that different network configurations are associated with the access and mobilisation of different types of resources. We developed a methodology that combines several methods usually applied separately and that permits to assemble of a vast array of data capturing the nature and contents of a wide range of relationships. This methodology was applied to a sub-set of the Portuguese biotechnology industry – the molecular biology firms. Globally this research provides evidence that contributes to on-going debates in the area of social networks and entrepreneurship, both at the methodological and empirical levels. At this stage the main contribution regards the development of a methodology that was found to offer important insights into the behaviour of science-based entrepreneurs in their search for key resources for firm formation. The results obtained, although still exploratory, already provide some indications concerning the conditions for biotechnology entrepreneurship in countries that are peripheral relative to the major concentrations of biotechnology knowledge and business
