The constituents of leaf essential oil of Juniperus oxycedrus L. subsp. oxycedrus (JOO) from wild flora of Gevas-Van in Turkey (Mount Artos) were studied using Gas Chromatography-Mass Spectrometry (GC-MS) and their antibacterial activities were assessed. A total of 18 compounds representing 99.98% of leaves oil were identified. The oils of the plant are all dominated by monoterpenes. The main compounds of essential oil in leaves were Limonene (45.77%), α-Pinene (23.94%), β-Phellandrene (10.83%), β-Pinene (5.68%), o-Cymene (3.30%), respectively. The essential oils were tested against Staphylacoccus aureus, Bacillus subtilis, Pseudomanas aeruginosa, Enterecoccus faecalis, Salmonella typhimurium, and Escherichia coli strains using the disc diffusion method. The diameter of the inhibition zones formed for bacteria were measured. The essential oils of JOO found to be active against all of the tested microorganisms and showed the susceptible inhibition zones. However, they were not as much as effective against bacterial strains when compared to ampicillin and ofloxacin. The extracts of JOO showed most significant antibacterial activity against Escherichia coli with inhibition zone diameter of 15 mm. The lowest inhibition zone diameter was Staphylococcus aureus with 11 mm.