The stem bark of Geoffroea decorticans (Gill.ex Hook. et Arn.) Burk. (Fabaceae) was used medicinally to cure several skin affections; however, previous phytochemical and biological antecedents that supported its vulnerary property were not found yet. A purified methanolic fraction from G. decorticans bark (PFGB), was derivatized by silylation for GC/MS analysis, and complementary analyses by two-dimensional TLC and UV-Vis spectroscopy against detected standards compounds. Nine phenolic compounds were characterized as gallic acid, quercetin, kaempferol, apigenin, protocatechuic acid, taxifolin, 4-Hydroxybenzoic acid; among these two methoxy-flavonoids. PFGB showed significant antibacterial activity (MICs= 125 μg/mL) against Staphylococcus aureus (25923) and Enterococcus faecalis (29212) ATCC strains. Cytotoxic effects on human lymphocytes activated or not by LPS were not observed up to 100 μg/mL, by MTT colorimetric assay. The resultsobtained through the ethnopharmacological approach of this work contribute to the scientific validation of the vulnerary medicinal use of G. decorticans.