The main goal of the present study was to investigate the chemical composition and the antimicrobial activity of Lavandula coronopifolia essential oil, collected in the southern region of Saudi Arabia. The essential oil of the airdried aerial parts of L. coronopifolia (Lamiaceae) was prepared by hydrodistillation method using a Clevengertype apparatus and analyzed by gas chromatography/mass spectrometry (GC/MS). The result of GC/MS analysis revealed the presence of forty six volatile components, 7 of which are aromatic and 39 are non-aromatic, representing 88.63% of the total oil. The main components were identified as phenol-2-amino-4,6-bis (1,1- dimethylethyl) (51.18%), carvacrol (4.35%), n-hexadecanoic acid (3.60%), trans-2-caren-4-ol (3.57%), 17- pentartiacontene (2.59%), caryophyllene oxide (2.16%), 1-hexacosanol (2.03%), 2,5-cyclohexadiene-1,4-dione, 2, 6-bis (1,1-dimethylethyl) (1.49%) and 5-amino-1-pentanol (1.23%) representing 76.45% from the total oil. The antimicrobial activity of the essential oil was assessed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Mycobacterium smegmatis and Candida albicans at a dose of 180μg/ml and showed no activity against all tested organisms.