In this study, Siğla (Liquidambar orientalis Mill.) storax (styrax) was investigated for antibacterial activity against Aeromonas hydrophila, Bacillus amyloliquefaciens, B. brevis, B. cereus, B. megaterium, B. subtilis, Corynebacterium xerosis, Enterobacter aerogenes, Enterococcus faecalis, Escherichia coli, E. coli O157:H7, Klebsiella pneumoniae, Listeria monocytogenes, Micrococcus luteus, Mycobacterium smegmatis, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens, Staphylococcus aureus and Yersinia enterocolitica. The storax was dissolved in absolute ethanol and was tested at concentrations of 10.0%, 1.0%, 0.4%, 0.2% and 0.1%. Pure ethanol was used for the control. The antibacterial activity of the Siğla storax was determined by using the agar diffusion method. The growths of A. hydrophila, B. amyloliquefaciens, B. megaterium, E. coli, E. coli O157:H7, L. monocytogenes and Y. enterocolitica were not inhibited by any of the concentrations of Siğla storax. The results showed that Siğla storax has antibacterial activity against many bacteria at concentrations of 10.0% and against some bacteria at concentrations of 1.0%, 0.4% and 0.2%.