Dichloromethane and methanol extracts from two argentine species of Gaillardia (Asteraceae): G. cabrerae Covas and G. megapotamica (Spreng.) Baker var. scabiosoides (Arn. ex DC.) Baker were assayed for their in vitro activity against two strains of Mycobacterium tuberculosis (H37Rv y MDR) by means of the TEMA colorimetric test. The minimum inhibitory concentration (MIC) in μg/ml was determinate. Dichloromethane extracts of both Gaillardia spp. and methanol extract of Gaillardia cabrerae exhibited antimycobacterial activity against both strains with a MIC range 50-100 μg/ml. The methanol extract of G. cabrerae was fractionated and two fractions were active. Phytochemical screening of the active fractions showed the presence of sesquiterpene lactones, aglycones and glycosilated flavonoids as main compounds.