In a previous study, we described the sesquiterpene lactones from Centaurea behen (1), Centaurea kotschyi (2), and the cytotoxic flavones from Centaurea urvillei (3).As a part of our continuing investigation, we now report the isolation, identification, and antibacterial activity of the flavonoids obtained from Centaurea virgata Lam., Centaurea kilaea Boiss., and Centaurea inermis Velen.A total of ten flavonoids were obtained from the samples of the above-mentioned species. Apigenin, the major compound, and jaceosidin were isolated from all of the species. In addition, isoschaftoside and isovitexin were isolated from C. virguta; hispidulin, eupatorin, nepetin, kaempferol 3-O-glucoside, and kaempferol 3-methyl ether from C. virguta and C. inermis; but only 6-methoxyluteolin 3',4',7-trimethyl ether from C. kilaea. All compounds were tested for their antibacterial activity by disc-diffusion methods (4, 5). None of them showed inhibitory effect on Staphylococcus aureus and Staphylococcus epididis. Only five of the flavonoids showed activity against the bacterial species given in Table 1, and this was at a low level with the most active being apigenin.