The paper explores the emersion and establishment of the Public-Private Partnerships (PPPs) in the context of the realisation of the Trans-European Networks (TENs). Since these latter require huge amounts of funding, the public sector needs the support from the private sector. In addition, because they do imply complex and long-term contractual arrangements, the endorsement and participation of the private subjects is necessary. As long as the private parties have to assume risks inherent to operations in the public interest, a certain framework so as to allow them to manage such a task must be assured. In essence, the Public-Private Partnerships (PPPs) consist of a quid pluris compared to concessions and represent a set of contracts, originated from the need to build the Trans-European Networks (TENs) aiming at the performance of services of general interest (social, environmental) and the formation, consolidation and growth of a true market of private capitals in infrastructures, which are at the moment hampered by the legal uncertainty that reigns in the sectorial European law.