P>This paper proposes that the mechanisms of external knowledge capture and internal knowledge transfer can best be understood at the micro-organizational level of Communities of Practice (CoPs) rather than at that of the subsidiaries' network. The paper then offers a model of the dynamics of organizational learning in network organizations, such as MNEs, which builds on this unit of analysis. This model: (i) clarifies the link between CoPs and Networks of Practice (NoPs), by offering a novel conceptual model of how knowledge, particularly tacit, embedded knowledge, is absorbed; and (ii) proposes a new link - that between CoPs and Internal Networks of Practice (INoPs), as another essential ingredient to knowledge accumulation and transfer within firms. We also propose that the firm-level architectural knowledge that is developed through INoPs is valuable and rare, and in combination with the component knowledge developed through NoPs, can create novel knowledge that may be a source of competitive advantage.