Bertholletia excelsa Bonpl. (Lecythidaceae) is a South American tree worldwide known for providing the Brazil nuts. In the Amazon Region, B. excelsa is found in monocultures, integrating agroforestries and providing raw materials for food and timber industries. Through the application of an integrative analysis based on high-performance liquid chromatography coupled with diode array detector and tandem mass spectrometry (HPLC-DAD-MS/MS) and nuclear magnetic resonance (NMR) techniques, the present study showed that B. excelsa bark biomass residues contain large quantities of ellagic acid (EA) and its derivatives. Qualitatively, five compounds were characterized for the first time in this species. Quantitations were carried out to determine the total amount of these compounds in outer and inner bark tissues. A total of 4.96 and 44.09 g of EA derivatives per kg of dry residues was determined for the outer and inner barks, respectively. Among the EA derivatives, eschweilenol C, ellagic acid and valoneic acid dilactone were the main compounds. These results pointed B. excelsa barks as a valuable biomass residue with potential to be source of health-promoting compounds. Therefore, a potential raw material as source of valuable bioactive phenolic compounds is described herein.