In Mexico, the decoction of the rhizome Krameria pauciflora is taken against diarrhea and dysentery. Our objective was to determine the antibacterial activity of Krameria pauciflora on the growth of the causal bacteria of gastrointestinal infections. 
 The plant was dried and pulverized at room temperature, this included the leaves, the rhizome, and the complete plant (stem–leaves–rhizome). These were macerated consecutively 48 h in hexane, dichloromethane, methanol, and water. Also, a decoction was prepared of the complete plant. The minimal inhibitory concentration (MIC) was determined by the method of resazurin. Dilutions were prepared, ranging from 5-0.039 mg/mL of the extracts, and we added these to plates that contained 5 x 105 colony-forming units (CFU)/mL/, resazurin sodium 0.675% and Müeller–Hinton medium (3X). Negative and positive controls were included with dimethyl sulfoxide 1% and Penicillin–Streptomycin, respectively. The bacteria utilized were: Escherichia coli; Proteus mirabilis; Shigella flexneri; Salmonella typhi, and Salmonella typhimurium. At least three assays were carried out in triplicate. 
 The decoction of the complete plant presented the greatest antibacterial activity, with an MIC of 0.078 mg/mL. The methanolic and aqueous extracts of the rhizome and of the complete plant presented a MIC of 0.156 mg/mL on Salmonella and Shigella flexneri, respectively. The hexanic extract of the complete plant inhibited all of the strains. The extracts of the rhizome and of the leaf, as well as of the dichloromethanic extracts of the rhizome, stem, and the complete plant, inhibited only S. typhi and S. flexneri.
 Keywords: Gastrointestinal infections, Antibacterial activity, Genus Krameria.