Information Systems (IS) offshoring is the transfer of IS services to a service provider outside the service consumer’s home country. The increasing amount of IS offshoring publications over the last years confirm the increasing interest in this topic. Furthermore, the transfer of knowledge from client to service provider poses major challenges in IS offshoring projects and directly affects IS offshoring success. Therefore, associated challenges must be overcome to achieve the resulting benefits. The dissertation aims to fill research gaps by investigating the following research questions: (1) What is the state of research in IS offshoring? (2) What are the characteristics of individuals conducting the knowledge transfer in an IS offshoring context? and (3) which determinants influence the knowledge transfer in IS offshoring? The answer to RQ1 aims to provide a conceptualization and the theoretical underpinning of the research field including a consolidated state of IS offshoring research. The results indicate that IS offshoring research is largely non-theory based, using almost entirely empirical data and interpretive research methods and - to a smaller extent - positivist research designs. The ISO research of the last 15 years focuses on the implementation stages 'how' and 'outcome' while the pre-implementation stages “why”, “what”, and “which” are comparatively sparsely researched. Future studies should apply a more theory-driven approach with a greater attention on pre- implementation aspects of information systems offshoring. RQ2 aims to understand the crucial role individuals must fulfill within the knowledge transfer process. The participants of the study agreed, with strong consensus, on a set of 16 tasks and 15 skills. The tasks focused primarily on relationship management and facilitating knowledge transfer on different levels. The set of skills consists of approximately 25 per cent “hard” skills, e.g. professional language skills and project management skills, and approximately 75 per cent “soft” skills, e.g. interpersonal and communication skills and the ability to deal with conflict. Two factors mainly influence implementing the offshore coordinator role: project size and the number of projects to be supported simultaneously. RQ3 aims to answer which determinants influence knowledge transfer in positive and negative ways. We identified 19 success and 20 failure determinants. These determinants are ranked in order of importance using best-worst scaling. Aspects of closer cooperation are critical for effective knowledge transfer. This includes regular collaboration, willingness to help and support, and mutual trust. In contrast, critical determinants of failure are concerned with fears and fluctuation of human resources. Hidden ambiguities or knowledge gaps, an unwillingness and disability to share knowledge, and high fluctuation of human resources negatively impact knowledge transfer. Overall, the dissertation consists of seven consecutive research articles. The results contribute to the understanding of IS offshoring in general and knowledge transfer in IS offshoring projects in detail. Furthermore, the results can facilitate organizations in ensuring their IS offshoring projects succeed.