The present study aims to analyse the impact of collaborative networks on a firm’s international presence in contexts of emerging clusters in transition economies. The empirical study conducted here focuses on a sample of 42 firms belonging to the Muntenia-Oltenia wine cluster in Romania. Social network analysis techniques and non-parametric tests were applied to address the research questions. Findings reveal that companies’ external resources, mainly their relationships with other firms and institutions in the cluster, are essential aspects in promoting their access to international markets. Furthermore, with regard to the relationships between cluster companies and institutions, our results suggest that trade support institutions are relevant in supporting these internationalisation actions, while technical support institutions do not influence the international presence of cluster firms. These findings provide relevant insights for companies, institutions, and policymakers on the best way to promote cluster firms’ international participation.