The purpose of this study was to elucidate the chemical composition and to evaluate the Antibacterial activity of the Algerian Artemisia herba-alba Asso (Asteraceae) essential oil (EO) from arid region (Naâma, Algeria). Volatile components of Artemisia herba-alba Asso essential oil obtained by hydrodistillation were analyzed by gas chromatography coupled with mass spectroscopy (GC-MS). The Antibacterial activity was assessed against four bacterial strains referenced by the ATCC (American Type Culture Collection) using the disk diffusion assay and the agar dilution method. Detailed analysis of the essential oils led to the identification of 80 components amounting to 99.44 % of the total oil. Chrysanthenone (22.99%) followed by camphor (18.72 %), α-thujone (9.85%), camphene (3.25),1, 8-cineole (3.19 %) and β- Thujone (3.05%) are found to be the major compounds. The antibacterial effect of the essential oil of Artemisia herba alba shows high sensitivity to most bacteria used at 5µl of pure EO and at 10µl except for Pseudomonas aeruginosa, which proved to be resistant. The minimum values of the inhibitory concentration (MIC) varied between 3.12 to 6.25 % (v/v).This plant can be used as potential alternative remedies for the treatment of many infectious diseases.