The process of globalization and the worsening of the competitive market have led organizations to seek new alternatives in their structures and their relations with other organizations and with the environment in which they are inserted. An alternative to get more competitive is the intensification and formalization of these relationships, which gives rise to organizational structures more complexs, with institutions that have intense interorganizational relationships. These types of organizational arrangements are fairly common in the health area, because those organizations need to relate closely with others to obtain the desired results. In this context, this paper aims to study a health organization with the objective to analyze the participation of various organizations present within its environment and how they influence their institutional standards. For this, had used a qualitative research, with the method of case study, being chosen for such a School Health Center of Faculty of Medicine of Ribeirao Preto. Data were collected through documentary analysis, observation and semi-structured interviews. Comparative analysis of the data was based on the theory, including concepts of organizational structure, institutional theory and administration projects. It was concluded that the School Health Center as a field of organizations with different goals in principle, but they converge in search of legitimacy. Moreover, in this field the projects implemented also institutionalize, which are based on services and increase the interorganizational relationships in this environment.