Background: The present work investigates the chemical composition, the antioxidant and the antimicrobial activities of the Essential Oils (EOs) of three species of the Lamiaceae family gowning in Algeria: Thymus vulgaris L., Thymus algeriensis Boiss. & Reut. and Mentha pulegium L. Methods: Essential Oils (EOs) obtained by hydrodistillation of the aerial parts of the studied plants were analyzed by GC and GC-MS. The antioxidant activity of the EOs was determined using two different assays: free radical scavenging activity of DPPH • (2,2-diphenyl-1-picrylhydrazyl) and Phosphomolybdenum reducing power. The EOs were also tested for their antibacterial and antifungal activities against eight pathogenic bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Methicillin resistant strain of S. aureus " MRSA " and Enterococcus faecalis); a yeast (Candida albicans); and a fungi (Fusarium oxysporum).