In this study, Antibacterial activity of garlic essential oil used by disk diffusion method, micro-dilution broth (minimum inhibitory concentration) and minimum bactericidal concentration (MBC) on a number of pathogenic strains (Pseudomonas aeruginosa, Escherichia coli, Listeria innocua and Staphylococcus aureus) was studied in vitro. Chemical compounds of garlic essential oil were identified by gas chromatography. The antioxidant potential, total phenol and flavonoid were determined using radical reduction capacity, Folin–Ciocalteu and aluminum trichloride colorimetric, respectively. The results showed that the minimum inhibitory concentration of garlic essential oil was 128, 128, 32 and 64 mg/ml for Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Listeria innocua respectively. By increasing the concentration of essential oil, the diameter of the inhibition zone increased. The highest inhibition zone with 31.70 ± 0.55 mmm diameter was due to Staphylococcus aureus. The results showed that gram-negative bacteria of Escherichia coli and Pseudomonas aeruginosa were the most resistant to garlic essential oil. The results of identification of the chemical compounds of garlic essential oil showed that the combination of di-allyl disulfide was 40.3% higher. Total phenol, flavonoids and antioxidant activity of garlic essential oil was 0.33 mg gallic acid in gram, 0.24 mg quercetin in grams and 80% respectively. The results of this study showed that garlic can be used as a potential source for the production of pharmaceutical compounds.