A big question for both academics and practitioners in ICKM is: How can human resource (HR) practices effect maximum leverage of the human capital pool in contemporary organizations through knowledge sharing? We know that HR practices are culture bound. The research evidence does not reinforce universal best HR practice because of the uniqueness of organizational cultures, comprised of both past and present social networks of employees providing both a historical and a current uniqueness in any organization. The resource-based theoretical view suggests that an organization's human capital pool is valuable. The empirical evidence reinforces this. The literature stresses the importance of knowledge sharing in the development of new knowledge for innovation and sustainable competitive advantage. So the nature and extent of knowledge sharing in an organization is also culture bound, and we suggest that organization culture becomes a mediating influence in the nature and extent of knowledge sharing, rather than simply HR practices. The role of culture as a mediator is often ignored or minimized in the practice of knowledge sharing. It is like the hidden part of an iceberg, and becomes visible when there is a clash between knowledge sharing activities and organization culture. So this is an important consideration to be included in knowledge management activities in organizations, and its role needs to be made clear. In this paper we review briefly the concepts of knowledge sharing, HR practices, and organizational culture, and the empirical literature of their relationships, in particular the role that culture plays in these relationships. The paper concludes with the development of a conceptual model of the role of culture as a mediator, which will provide the framework for future research in this area to test its importance.