Zornia brasiliensis (Leguminosae) is a species popularly known as "urinary", "urine" and "burrow" and its popular use is reported as a diuretic and for treatment of venereal diseases. It occurs in several states of Brazil, being abundant in the Northeast. Therefore, this study aims to contribute to the chemical knowledge of this species through an HPLC-DAD-MS/MS study for the rapid determination of saponins. Aerial parts of Z. brasiliensis were collected in Serra Branca, state of Paraiba. An exsicata was deposited in the Herbarium Arruda Câmara (ACAM) of Campus I of UEPB. After drying and ground, the plant material was subjected to a 95% ethanol maceration for 72 hours, and this process was repeated four times to obtain the crude ethanolic extract (CEE). An aliquot of the CEE (100.0g) was subjected to vacuum liquid chromatography (VCL) with silica deactivated with hexane, dichloromethane, ethyl acetate and methanol solvents. An aliquot of the 50% acetate-methanol fraction was subjected to a specific methodology for the concentration of saponins. This fraction was then analyzed by HPLC-DAD-MS², allowing the identification of a triterpenic saponin, suggesting to be the Soyasaponina IV, described for the first time for the genus Zornia. In this way, this work contributed to the chemistry Z. brasiliensis and corroborated with the chemitaxonomy of the family Leguminosae.