Facing a phase of liberalization and deregulation, the relation between cities and ports has been thoroughly analyzed from different perspective in the last 50 years. Beyond simple coexistence, the issue is the creation of synergies benefiting to both entities. These movements have an impact on the new trajectories of governance and partnerships between public and private actors. So port governance is marked by a new level of complexity which has caused a reshaping of the system of actors involved in the organization of ports. Consequently, the paper aims to provide some insights into this question by presenting the first results of a research project focusing on the relationship between ports and territories which are numerous. Likewise, the paper also seeks to identify the characteristics, constraints and dynamics of the relationship between ports and cities and to study their potential impacts on spatial planning and territorial development. It specifically focuses on an intermediate scale of port-cities. The methodology of this paper is primarily qualitative and based in part on interviews conducted among key actors and field studies. It mainly emphases on interrogations about the institutional status of the ports, the issues and consequences of the choices or the role of each category of actors in port and/or city governance. This analysis of decision-making processes will allow to describe and explain the dynamics of cooperation, but also conflictual logics.