We suggest that the development and sustainability of Knowledge Sharing (KS) networks requires an understanding of the interplay between Organizational structure (OS), communications network and KS practices in organizations. We suggest that the application of a fundamental social theory (e.g., The Elementary Theory of Social Structure) is a useful paradigm for understanding the development and management of KS networks from both a theoretical and an applied perspective. We argue that organizations need to design and manage legitimate network (i.e., formal) structure so that it can promote both the development and sustainability of shadow network (i.e., informal and “tacit”) structure. A Mech-Organic Perspective (MOP) based on an understanding of the mechanical (i.e., theoretical and/or applied) and organic (i.e., conceptual and/or subjective) components of communications network is introduced. Implications of MOP for the study, design, and management of learning organizations are discussed.