Beside the formal organization there exists the very powerful informal one. There is a series of similarities between them, of which the following stand out: a structure of relationships, a system of control, communication, persons with authority, perception of the consequences of an act, relative permanence of the members and possibility of graphic representation. Since the informal organization is undestructible, it is recommended that the same organization be used by the formal, which is viable, bringing general benefits. Some forms of informal organization study are presented in the present paper.