While studies on shamanism have experienced a renewed interest in ethnological literature for some years, particularly due to the renaissance of phenomenon in certain areas that are particularly threatened or too brutally exposed to cultural change, it is interesting to note that it is above all the role played by hallucinogens in the shamanic complex which seems to have been given priority to the attention of ethnologists, particularly American. However, it is not assured of the fertility of such a concern, particularly in view of the relationship between hallucinogens and culture (Furst, 1980), it is necessary to consider the basis of the taking of psychotropic substances directly affecting shamanic practice and how a society apprehends the world, or is it only marginal experience without any real social and cultural scope? In other words, does hallucinogenic experience intervene actively in people's life and thought, or is it only the projection, in sum of negative terms, of particular cultural forms? The purpose of this article is to identify, from an internal vision to society in question, the role and importance of hallucinogens in the Peruvian forests by Yagua, in particular in relation to Shaman practices, as a means of access to knowledge on which their system of thinking is based and from which any Shaman approach is ordered. We will also show that, while hallucinogens are at the centre of the initiative experience of Shaman, they lose their importance once the knowledge gained, playing a less role in the Shamanic practice and in the daily life of the group, although the Yagua say to find in drugs the source of any creative inspiration and, thanks to the gifts of the foresight they provide, the solution to many types of interpersonal conflicts, both within and outside society.