The essential oils obtained by hydrodistillation from the leaves and bulbs of Gynandriris Sisyrinchium L. growing in the northern region of Jordan (Irbid) were investigated by GC and GC/MS. The major constituents of the leaves oil were 3,7,11,15-tetramethyl-2-hexadecen-1-ol (20.24%), ledene oxide (II) (12.62%), furfural (9.80%) and trans-sabinol (3.58%). The bulb oil was found to contain phenylacetaldehyde (21.85%), 8,9-dehydroneoisolongifolene (12.10%), 8S,14-cedranediol (8.36%) and furfural (3.66%) as the major constituents. The antibacterial activity of essential oils mixture of the bulbs and leaves were evaluated for their antimicrobial activity against ten bacterial isolates using agar disc and agar well diffusion methods. The Gram-positive bacterial isolates including Bacillus cereus, ATCC11778 and Bacillus subtilis, ATCC6633 were the most susceptible to the tested oil mixtures. In contrast, the tested essential oils showed either no inhibitory effect against Klebsiella pneumoniae, ATCC 10031 and Serratia marcescens, ATCC 27117 or moderate effects against the remaining tested Gram-negative bacterial isolates.