This article examines the therapeutic practices of the inhabitants of Jau National Park (JNP), state of Amazonas, the most important feature of this region being its rich biodiversity associated with isolation in regard to conventional medical services. Seven months of field work were guided by methods of anthropology and botany. A total of 120 plants and 29 animals were utilized in 519 recorded uses comprising 81 therapeutic purposes. These were grouped under 15 categories of use, including: gastrointestinal disturbances, inflammatory processes, genitourinary disturbances, fever, mishaps with animals, dermatological problems, pain, osteo-muscular problems and tropical diseases. Those who administer these medicines are local residents specializing in household remedies and other groups of healers such as rezadores-prayer-maker; curadores-healers; parteiras-midwives; desmintidores-masseurs and mediuns-mediums. At least 10 of the 120 plants species cited in this study are also utilized by other inhabitants of the Amazon region and for the same uses; some of these plants had already been studied from a pharmacological point of view. Furthermore, another six plants cited by the JNP caboclos belonging to the categories pain and inflammatory processes, are under investigation by groups of researchers in two Brazilian federal universities. Copyright (c) 2006 John Wiley & Sons, Ltd.