The species Phlebodium decumanum is an ethnomedicinal resource in several native communities in America. However, little chemical information is reported for the rhizomes, which are also used medicinally. Therefore, the objective of this study was to evaluate the phytochemical profile of the hydroalcoholic extract of P. decumanum rhizomes through identification by UPLC-MS/MS, as well as its phenolic and flavonoid content. As a result, 22 substances were identified, with emphasis on phenolic acids, flavonoids and hispidin, which in turn, have biological activities that can explain the relationship of this natural resource with ethnomedicinal use.