The purpose of this article is to focus on an important issue in the field of public policy, i.e.: the role of consultants in the process of public policy and decision making. In this article, it is historically shown that this role was confirmed and applied in ancient civilizations such as Iranian, Greek and Islamic civilizations. The systematic role of consultants is, then, emphasized in modern states like France and the U.S.A.
The case of I.R. of Iran is taken under consideration from two points of view: firstly, an overall observation in order to provide a typology of consultants in this country; secondly, a clinical observation, by taking an institution as case, to see how manger, in one side, and consultants, in other side, see the characteristics, the importance and the place of this function in their organizational life.