In technology intensive sectors, where knowledge is complex and distributed, young, small firms will tend to resort to external organisations to obtain scientific and technological knowledge. The need to gain access to external resources and competences leads firms to mobilise relationships that can facilitate such access. Research on social networks can therefore provide an important contribution to the understanding of these processes. This paper analyses the networking strategies of firms from two sectors and its objective is to understand: 1) whether there is heterogeneity in the networks built by firms for accessing resources necessary for innovation; and 2) whether such heterogeneity can be associated to differences in the technological regimes under which these firms are operating (main research question). To address these questions we draw mainly on two streams of literature: social networks and technological regimes. For our purpose, we have selected young firms operating in molecular biology and in software for mobile telecommunications, usually associated to different technological regimes. It was found that technological regimes, both sector-based and sector-independent, influence firms’ network strategies. Interestingly, the former explains differences in network composition while the latter explains differences in the perceived importance of the network. However, none of them appears to influence network structure (density). The results of this analysis have enabled us to uncover the intra-sectoral variety of technological regimes and allowed a better understanding of the relationship between the nature of technological regimes and the strategies of network building by the firms.