abstract the essential oils of fresh aerial parts of satureja abyssinica (benth.) briq. ssp. abyssinica and satureja paradoxa (vatke) engl. collected in ethiopia were analyzed by gas chromatography (gc/fid) and gas chromatography-mass spectrometry (gc/ms). the results of the analyses indicated that the components of the two oils are similar qualitatively with significant quantitative differences. twenty-three compounds comprising 96.9% of the total peak area were identified in s. abyssinica ssp. abyssinica oil with the monoterpene ketones pulegone (43.5%) and isomenthone (40.7%) as major components. the oil of s. paradoxa was found to contain twenty-six compounds comprising 92.0% of the total oil with the major components being cis-piperitone oxide (45.3%), pulegone (9.3%) and piperitenone oxide (8.1%). the in vitro antimicrobial activity of the oils was studied against some medically important pathogens including gram positive and gram negative bacteria as well as some fungal strains using standard agar-well diffusion technique. both oils exhibited significant activity against most of the bacteria and fungi used in the study with minimum inhibitory concentration (mic) values ranging from 0.50 to 4.00 l/ml, against the bacteria, and 0.19 to 3.00 l/ml, against the fungi. comparison of their activity with standard antibacterial and antifungal agents revealed that both oils were more active against streptococcus pyogenes than the standard antibiotic amoxicillin. moreover, the oil of s. paradoxa displayed a powerful activity against candida albicans and trichophyton mentagraphytes with growth inhibition zone greater than that of the standard antifungal agent ketoconazole. the oils were also tested for their antioxidant activity in diphenylpicrylhydrazyl (dpph) assay and showed a dose dependant free radical scavenging activity with ic50 values of 1.8 l/ml (s. abyssinica subsp. abyssinica) and 1.6 l/ml (s. paradoxa).