The social sciences have often used leadership as a concept to describe the role of agency in change. Nonetheless, what leadership is and does may not always be clear, especially in the loose networks of local governance. On taking a policy analysis perspective, policy leadership in cities can be seen as coordinated action to achieve a shared goal taken by more than one leader, each endowed with different resources that may suddenly become strategic during the policy process. This paper thus proposes a theoretical reflection on policy leadership and uses a case study in urban planning to unpack power relationships involved in policy change at the municipal level. The contribution of the paper is twofold. First, it clarifies the concept of leadership in different social sciences and proposes an original application to the analysis of the policy process in local governments based on a typology of styles of policy leadership and a classification of strategic resources. Second, it argues for the existence of a policy leadership in the process of urban planning in Turin (1993-2011) as a key component of the complexity of urban governance, by focusing on the situated and strategic nature of exchange relationships.