Tannins (polyphenols) are found in high concentrations as chemical components of extracts of some plant species. A sign of the presence of tannins is causing astringency. They are water soluble and possess the power of precipitating and complexing proteins. These characteristics provide several applications and multi-use. Beyond the direct medical application, the products of these plants are used in industries (pharmaceutical, lumber, food), in tanning and water treatment. The biological properties of tannins are the reason for its use as an insecticide, fungicide and bactericide. In folk medicine plants with high levels of tannins are mainly applied as healing (A), against inflammation (B) and infections (C). Medicinal plants species native at the heart of South America, Brazil, in cerrado areas (eg, Mato Grosso) are used extensively by the people as medicine and are rich in tannins. Among them we have: I – Caju-do-campo (Anacardium humile A.St.-Hil.), II – Aroeira-preta (Myracrodruon urundeuva Allemão), III – Barbatimião-preto (Stryphnodendron adstringens (Mart.) Coville), IV – Barbatimão-branco (Dimorphandra mollis Benth.), V – Angico1 (Anadenanthera falcata (Benth.) Speg.), VI – Angico2 (Anadenanthera colubrina (Vell.) Brenan), VII – Angico3 (Albizia niopoides (Spruce ex Benth.) Burkart.), VIII – Cumbaru (Dipteryx alata Vogel). Only two plant families include the 8 species listed: Anacardiaceae (I, II), Fabaceae (III, IV, V, VI, VII and VIII). Besides the typical applications (A, B, C) of medicinal plants rich in tannins, species I is also used to control diabetes. For the population, the potential of these plant resources must continue to be studied more, to better orient right policy for rational exploitation and sustainable.