[Institution of nurse's leadership in health matters]

The subject matter in focus in this research was the fact of nurses begin to work in the management leadership at the Municipal Health Foundation of Niterói (FMS). The Institutional Analysis, René Lourau trend, was the method used for analyzing the relationships established by 10 nurses acting as health managers. The "theoretical base" was constructed by oral activity of the agents, through an oriented interview, limiting three categories: "The Challenge of Being a Manager", "The Challenge of Being a Leader" and "The Challenge of Decision Making". Among the knowledge constructed one can points out the CHALLENGES that the nurse has to face in the health management, which are: to organize the work of other professionals and to take charge in fact of the leader role in the health system.