Abstract: The aerial parts of Salvia spinosa L. (Labiatae) afford an essential oil on hydro distillation was analyzed by gas chromatography-mass spectroscopy (GC/MS) using direct injection. Out of 19 peaks (representing 99.99% of the oil), 18 Components were identified representing 98.59% of the total oil Composition. The major Components were 1,8-cineol (32.87%), (Z)-β-ocimene (20.03%), Germacrene d (10.66%), 2-Butyl thiophene (9.83%), Trans caryophyllene (5.01%) and 3- Butyl thiophene (3.49%). The oil was also screened for its antimicrobial activity against four bacteria (Staphylococcus aureus, Basillus subtilis, Psedomonas aeruginosa and Escherichia coli) and two fungal strains (Candida albicans and Aspergilus niger) using Disc diffusion method and also Minimum Inhibitory Concentration (MIC) values of each active oil concentration were determined. The results showed a significant activity against Staphylococcus aureus, pseudomonas aeruginosa and Basillus Subtilis.