The results of the first detailed study of the use of medicinal plants by a group of Yanomami Indians are presented. Contrary to previous assumptions, they are shown to possess a substantial pharmacopoeia, including at least 113 species of plants and fungi. The changes in their use and knowledge of plant medicine are discussed in the context of the past and present influences on the Yanomami by the outside world. Key Words: Yanomami; medicinal plants; AmazGnia; phytotherapy; intellectual property rights.