the essential oils of rosemary ( rosmarinus officinalis l.) and sage ( salvia officinalis l.) were analyzed by means of gas chromatography-mass spectrometry and assayed for their antimicrobial and antioxidant activities. antimicrobial activity was tested against 13 bacterial strains and 6 fungi, including candida albicans and 5 dermatomycetes. the most important antibacterial activity of both essential oils was expressed on escherichia coli, salmonella typhi, s. enteritidis, and shigella sonei. a significant rate of antifungal activity, especially of essential oil of rosemary, was also exhibited. antioxidant activity was evaluated as a free radical scavenging capacity (rsc), together with the effect on lipid peroxidation (lp). rsc was assessed by measuring the scavenging activity of essential oils on 2,2-diphenyl-1-picrylhydrazil (dpph) and hydroxyl radicals. effects on lp were evaluated following the activities of essential oils in fe(2+)/ascorbate and fe(2+)/h2o2 systems of induction. investigated essential oils reduced the dpph radical formation (ic50 = 3.82 microg/ml for rosemary and 1.78 microg/ml for sage) in a dose-dependent manner. strong inhibition of lp in both systems of induction was especially observed for the essential oil of rosemary.