The growing population of drug-resistant microorganisms and the problem of treating the infections induced have motivated the search for alternative antimicrobial drugs in lichens. The methanol extracts prepared from some common lichens species were evaluated for antibacterial activity against standard strains (Escherichia coli, Bacillus subtilis, and Staphylococcus aureus). the tested extracts showed more potent inhibitory effects on Gram (+) bacteria than on Gram (-) bacteria.