In another contribution in this encyclopedia, we presented the construct social structure as the context in which interactions between CoP members take place. Social structure has been defined along several dimensions, for example, group (CoP) longevity, norms for conflict resolution, and coordination of daily exchange. It has been disputed whether social structure can be deliberately influenced by management, that is, whether CoPs represent a social collective that is manageable to a degree as in, for example, a formal project team. In this article, we argue that the social structure of CoPs can be influenced by using a certain leadership style as an influence tactic. We believe that for influencing the kind of social structure proposed for CoPs, transformational leadership is most suitable.