The ayahuasqueros I have been with are culturally mixed Indians. They are not what an anthropologist would call pure shamans (they rarely define themselves as such, preferring the terms of curandero, vegetalista, ayahuasquero, or pajé) as, in so far as, no longer living in traditional and isolated Indian communities, they have abandoned certain aspects of the charge of shaman such as war and hunting for example. They are now more oriented towards the role of healers, seeking to expand their knowledge of medicinal and magical plants. I think some of them are still great masters of ecstasis. Their vision of life and universe, although very far from Western conception, is of great consistency, provided, additionally, rigour and poetry. In this context, man, through learning and knowledge, is changing into actors in the universe where his poor condition should, according to our conception, be restricted to the state of object. Archaeological research shows that men have been using ayahuasca for over three thousand years in the Amazonian basin. It is one of the magnificent discoveries of Indians who, among the hundreds of thousands of plants of their biotopes, have been able to select, extract, mix elements to prepare complex and fearably effective mixtures. Millions of possible combinations of parts of plants (seeds, roots, barks, leaves, etc.), their dosing, preparation (raw, boiled, smoked, etc.), associated with the various ways of using them, by absorption, inhalation or skin contact, make it possible to ask themselves solid questions about the empiricism of their discoveries. The accidental experimentation is not realistic. Indians claim that it is the plants themselves that teach men how to use them. A vast subject which, if we are to be found on the side of the natives of the forest, makes it enter the shamanic universe from the outset ... The following pages are the story of the journey I have undertaken in this unknown world, and have no claim of anthropological or scientific character. This document is the simple chronic of different stays made with Peruvian ayahuasqueros.