abstractthe essential oil from leaves of nectandra antillana meisn. grown in cuba was isolated by hydrodistillation and analyzed by gas chromatography/flame ionization detector (gc/fid) and gc/mass spectrometry (gc/ms). one hundred and fifty compounds were identified and quantified, accounting for 99% of the total composition. the essential oil was rich in sesquiterpene compounds, particularly caryophyllene oxide (16.0%), -caryophyllene (9.9%) and guaiol (8.7%). the in vitro antibacterial activity of the essential oil was studied against five bacteria strains (bacillus cereus, bacillus subtilis, escherichia coli, staphylococcus aureus and listeria monocytogenes) using the disc diffusion method. the essential oil was slightly effective against nearly all bacteria tested, except for b. subtilis.keywords: nectandra antillanalauraceaeessential oilgas chromatography-mass spectrometryantibacterial activitycaryophyllene oxide-caryophylleneguaiol acknowledgementwe are grateful to dr. pedro herrera (instituto de ecolog'ia y sistem'atica, la habana, cuba) for identification of the plant specimen.