The volatile compounds obtained by hydrodistillation of the aerial parts of Rosmarinus officinalis cultivated at the Algerian Sahara were analyzed by GC/MS. Thirty compounds were characterized representing 98.2% of the essential oil with 1,8-cineole (29.5%), 2-ethyl-4,5-dimethylphenol (12.0%) and camphor (11.5%) as the major components.