Though International Joint Ventures (IJVs) are widespread, their high failure rate, attributed to the difficulty of managing them, has increased interest in their management. IJV research has seen knowledge sharing and learning between partners to be essential for success, and has noted that this is easier when the international partners are culturally aligned with one another. The process of integrating knowledge across national boundaries and between people from dissimilar cultures is a challenge, because it requires the firms to be embedded into the local market. IJVs need to ensure appropriate approaches for acquiring the knowledge and learning they require. The purpose of this thesis is to examine the knowledge sharing and learning processes that IJV managers undertake, focusing on the “micro-level” of IJV manager action and interaction. It explores how managers of the partners and of IJVs overcome barriers to knowledge sharing. This research combines internationalisation process, knowledge sharing and organisational learning research to develop an overarching theoretical framework for IJV learning that positions the IJV managers’ roles within the learning process within IJVs. It then examines theoretical ideas concerning the ‘microfoundations’ of learning to consider the structural arrangements, the individual capabilities and the organisational processes of the IJV that might help IJV managers to learn from their partners, to develop capacity within their IJV, and to help the internationalisation of their partners. This study explores knowledge sharing and learning within the highly successful Samsung-Tesco Homeplus retail IJV formed in 1999 in South Korea as part of Tesco’s internationalisation process. The retail context is appropriate to study the concepts of IJV learning, because retail businesses need to be highly embedded in their market through strong ties with their local customer base, which increases the need for internationalising retail firms to gain knowledge and learning from local IJV partners. The case partner firms, having complementary resource bases but facing barriers of dissimilarity (Korean electronics manufacturer and UK retail firm), yielded a rich context for examining how these were overcome to achieve learning. Data from semi-structured interviews with top and middle level managers and industry experts were triangulated with multiple sources of secondary data. A microanalysis approach for data analysis enabled analytical abstraction to theory. The study draws three broad findings regarding the overarching theoretical framework for IJV learning. First, IJV partners can themselves develop strategies that help knowledge sharing that will enhance the prospects for IJV success. The IJV partner’s prior capabilities are critical for building and sustaining their IJV relationship prior to and during the IJV. These capabilities facilitate cross-fertilization, integration, and combination of new knowledge and learning between the partner’s prior bodies of knowledge, helping knowledge application to be focused on the IJV’s needs. This, in turn, helps an absorptive capacity building process to be generated within the IJV itself.