Awaju'n society (Jivaro group, Peru) has two health specialists, the shaman and the herbalist, identified by their use of four psychotropic plants during their apprenticeship and practice. These plants enable the two specialists to make contact with the invisible, or the spirit world, and acquire knowledge and power. After a brief presentation of Awaju´n society, the text describes these four plants and the use made of them. We will see that this capacity to see the invisible comes from lengthy training and the acquisition of knowledge transmitted from generation to generation through the plants. Keywords: Awaju'n – Peru – Shamanism – Psychotropics Modified states of consciousness