With the development of globalization, companies will need worldwide resources for R&D. Multinational corporations (MNCs) will rely on their subunits located in different countries for R&D. As a result, knowledge transfer between headquarters and subunits or among subunits will be crucial for MNCs to operate their R&D activities. This study explores the relationship between knowledge transfer and R&D operations, using a qualitative research approach including four multinational companies. We conducted a cross-case analysis connecting four R&D configurations and two knowledge transfer mechanisms: expatriate management policy and communication frequency. Results show that both transfer mechanisms are very important for MNCs for the management of knowledge transfer in global R&D operations. However, each of these mechanisms will need different a focus depending on R&D strategy and configuration. The article summarizes recommendations for managers as drawn from these insights. © 2015 World Scientific Publishing Company.