A biochemical characterization and study of the biological activities of the aerial parts of Artemisia campestris and Ruta chalepensis were carried out. GC-MS chromatographic analysis of essential oils showed a predominance of monoterpenic hydrocarbons for A. campestris and ketones for R. chalepensis. Our results showed that the extraction solvent significantly affects the levels of total polyphenols, flavonoids and condensed tannins in the aerial parts of both plants as well as antioxidant activities. The methanolic and ethanol extracts have stronger anti-free radical activities than the aqueous extract. The results of the antimicrobial activity showed that these essential oils and extracts (methanol and ethanol) have a strong antibacterial activity. The inhibitory effect of essential oils and extracts of methanol and ethanol of both plants on bacterial and fungal development gives them an important role in the food industry as an additive in foodstuffs or in packaging, cosmetics and pharmaceuticals.