Background: Due to the increased knowledge gaps that originate from rapid technological change, many organizations are in need of consulting services. As of this, the consulting market has had rapid growth, which has caught the attention of scholars. Previous research has identified an interface between knowledge and identity as two prominent concepts when analyzing the client-consultant relationship. Despite this, there is still a great lack of empirical insights regarding how these two concepts might affect this relationship. Purpose: The purpose of the study was to explore knowledge transfer within the client-consultant relationship by applying the lens of role identity. Furthermore, the research aimed to increase the understanding of the barriers to knowledge transfer, where they originate from,and how to overcome them. Method: This research is of a qualitative sort, where abductive reasoning has been applied in order to fulfill our research purpose. Furthermore, a single case study approach was conducted and data was gathered from interviews with both consultants and clients. The gathered data was analyzed by using grounded analysis, where insights have been identified by creating 1st order concepts, 2nd order themes and aggregated dimensions. Conclusion: The result of this study indicates that different idiosyncratic and conventional role identity meanings create mismatches within the client-consultant relationship. The concept of role identity ambiguity creates barriers for securing knowledge transfer within the client-consultant relationship, and knowledge transfer outcomes affect future role identity meanings. The result of this study contributes to already existing literature regarding role identity, knowledge transfer and the client-consultant relationship. Furthermore, the study presents managerial implications that will increase consultants' understanding of the barriers and suggestions for how to overcome them.