Institutional constraints and the web of social relations influence key organizational dimensions and hinder their decisional capacities, even determining a moving away from any pre-established rational goal. This chapter focuses on the relationship between institutions organization within the external environment. It begins by defining the external institutional environment, the dimension of the organizational field and by describing legitimation mechanisms and isomorphic processes. It then moves towards the presentation of the Institutional-Based View, first introducing market problems and market ordering mechanisms.