Studying collaborative relationships between the public and private sectors concurs to the knowledge of contribution in promote economic development, regeneration of urban and rural areas, through the participation of a wide range of actors belonging to central/local governments, private actors. The institutional system where the public-private partnerships evolve, offers to governments, the possibility to make their contribution in drawing up sustainable agreements through creating new institutionalstructuresthat provide a framework conducive to coherent policies formulation and experience development in project management. The institutional framework of the public-private partnership develops regulatory instruments through which it exercises its influence in the development of partnerships. The state establishes units of Public-Private Partnership type, their role being to make their contribution in solving problems regarding PPP - designing partnership projects in a wide range of areas and implementing their goals. These units can contribute with information in formulating national policies and practices, thus, supporting government in developing partnerships. The paper presents aspects of the institutional framework where Public-Private Partnerships form and evolves and elements whereby it takes part in their development – the institutional instruments and Public-Private Partnerships Units - the opinions of different authors concerning the influence which the institutional framework exerts on public-private partnerships.