The secretory elements of the essential oil fromColeus aromaticusfrom Martinique were observed under the scanning electron microscope. The composition of the oil was analyzed and found to consist mainly of phenoh'c components, with carvacrol (72%) being the major compound. Five compounds were identified for the first time in the oil ofC. aromaticus.They were (Z)-1,3-hexadiene (0.1%), (Z)-3-hexenol (0.6%), (E,Z)-α-farnesene (0.2%), (E.E)-α-farnesene (0.2%) and α-muurolene (0.2%). The biostatic activity of the leaf oil was tested on six bacterial and six fungal strains. It was found to have activity againstVibrio cholerawith a MIC of 0.125 mg/mL.