The aim of the present investigation was to appraise variation in the chemical composition and antimicrobial activity against phytopatogenic bacterial of essential oils from Azorella spinosa. Three samples of A. spinosa were collected in different date in the same area. The essential oils were obtained for hydro-destillation using a Clevenger-type apparatus. The chemical composition of essential oils were analysed using Gas chromatography-mass spectrometry showed variation in the yield and composition, the main detected compounds were monoterpenes such as limonene (10.66-12.30%), tricyclene (10.81-16.99%) and sabinene (9.10-11.49%), the most abundant sesquiterpene was γ-gurjenene (5.48-8.47%). The biological activity of essential oils from A. spinosa against wild phytopatogenic microorganisms showed selectivity over Pseudomonas syringae. This is the first report of the essential oil composition of A. spinosa, and confirms that natural products obtained from aromatic plants represent an important source of bioactive molecules that could be used as new alternatives for the treatment of phytopatogenic bacteria infections.