Purpose: This paper aims to draw on the network perspective of firm internationalisation to study how an intermediary network actor, such as an export promotion organisation (EPO), can influence the internationalisation of new ventures located in peripheral regions. Design/methodology/approach: The paper employs case analysis and the critical incident technique to study the influence of the Irish Government's support agency for the seafood industry, Bord Iascaigh Mhara (BIM), on the internationalisation of three new ventures in the seafood sector in the West of Ireland. Findings: The EPO played an important role in information mediation: identifying foreign opportunities and customers; facilitating introductions to international customers; and by providing foreign market knowledge; and as a resource provider developing the firm's export capacity. Research limitations/implications: The choice of sector and method may impact on the ability to generalise the findings to firms in other contexts. Practical implications: This study identifies a number of important implications for managers. It identifies a dilemma for policy-makers: do efforts to develop strong support agencies come at the expense of developing strong firms? Originality/value: This study advances the understanding of the role of an intermediary network actor in influencing new-firm internationalisation. It identifies a set of conditions that, it is argued, are necessary if an EPO is to facilitate firm internationalisation. © Emerald Group Publishing Limited.