The researchers in the field of Altered States of Consciousness have always underlined the importance of chemical substances to induce such peculiar states. Their studies have emphatized the importance of an appropriate environrnent and psychological expectation. When these points are taken into consideration, the experience induced from psychotropic plants are not only useful but often show some therapeutic and parapsychological effects. To recreate this opportunity different cultures alI over the word have elaborated particular «maps» to guide the adept during the state of alterations of his spatial-temporal coordinates involved by the use of these plants. This paper deals with the use of an hallucinogenic brew, ayahuasca, and its shamanic context of Peruvian Amazon and particularly its integration in a "map" of shamanic apprenticeship. To study the use of ayahuasca only from a chemical-pharmacological point of view probably means to take into consideration the less significative features of an ancient, but still living, wisdom.