The literature suggests that board directors of international joint ventures (IJVs) can play a crucial role in IJV success. This is due to the fact that the partners' representation on the IJV board is their only direct, legal connection to their IJV. However, the presence of two or more partner organisations of different national and organisational cultures and divergent agendas about their IJV could provide major challenges to IJV board directors. Generally, it can be concluded from the literature that IJVs, due to their shared governance structure, require unique leadership capabilities. However, despite the acknowledged importance and potential complexity of IJV board director role, little consideration has been given by researchers to the IJV board directors. Prompted by the view that the literature provides very little actual evidence about leadership capabilities in the context of IJVs, this paper presents empirical evidence concerning the IJV board directors' knowledge, skills and behavioural dispositions that have been associated with a positive performance in their role. The findings are based on qualitative exploratory case studies of board directors from Serbian-foreign joint ventures based in Serbia, as a part of a wider enquiry into IJV director contribution to board effectiveness. The IJV director's knowledge of business (being informed and prepared), cross-cultural, language and interpersonal skills, a positive attitude, willingness to make an effort to understand the other partner's point of view, objectivity, reliability, and motivation and commitment, emerged as important leadership capabilities in the IJVs. They are seen to facilitate balancing different partners' agendas, increase inter-personal and inter-partner trust, openness of communication and efficiency of board decision-making, and ultimately contribute to IJV success. The paper outlines contributions to role, corporate governance and IJV literatures and also offers methodological and practical implications.