Abstract The Brazilian Cerrado has several botanical species for medicinal purposes used by traditional communities and many of these plants are not included in the list of Medicinal Plants Research Program of Central Medicines. The purpose of this study was the phytochemical screening and toxicology bioassay front of Brine shrimp L. of ethanolic extracts of eight species of plants used in folk medicine of Campo Grande, Mato Grosso do Sul, Brazil. The ethanolic extracts were submitted to phytochemical screening, determination of phenolic compounds and flavonoids. Toxicological assays were carried front of Brine shrimp according to standard methodology. The analysis TLC and HPLC-DAD confirmed the predominance of phenolic compounds and derivatives, specifically for the quercetin. The most toxic was the C. affinis DC. with death at all concentrations, the A. humile A. St. Hil. showed no mortality and the other species showed intermediate toxicity. The extracts of the investigated species are rich in phenolic compounds and derivatives, specifically quercetin, and feature toxicity between moderate to high, a fact that requires attention, since much of the traditional communities rely on herbal drugs in its raw form with preventive and curative purpose, meeting the basic health care.