This study was carried out to determine antibacterial activity of essential oils, extracts and major components of three Artemisia species (A. absinthium, A. santonicum and A. spicigera) against to some seed borne bacterial plant pathogens. According to our results, essential oils and some major components of Artemisia species have antibacterial activities at varying rates while extracts have shown no activity against any of the pathogens. Disc-diffusion method was used to test antimicrobial activity of the essential oils and extracts According to the results obtained, essential oil of A. santonicurn has antibacterial effect against to 24 of 25 bacterial strains, essential oil of A. absinthium has antibacterial effect against 15 of 25 bacterial strains and essential oil of A. spicigera has antibacterial effect against only three of 25 bacterial strains. Additionally, constituents of the essential oils were analyzed by GC MS method. Camphor, caryophyllene oxide, linalool, 1,8-cineole, teminen-4-ol, borneol and alpha-terpineol were determined as predominant components. Minimum-maximum inhibition zones and MIC values of linalool were 8 mm (C. violaceum RK-231) - 45 mm (X campestris pv. vitians RK-Xcvi), 50-110 mg/ml; terpinen-4-ol 8 mm (B pumilus RK-106) - 43 mm (X campestris pv. vitians RK-Xcvi) and MIC values 60-110 mg/ml; alpha-terpineol 8 mm (P.cichorii RK-166 and X axamopodis pv. vesicatoria RK399) 10 mm (P. huttiensis RK-260 and P. syringae pv. syringae RK-204) and 60-70 mg/ml, respectively. But caryophyllene oxide, bomeol, camphor and 1,8-cineole didn't show activity against any of the pathogens. In sum, our findings suggest that essential oils may be valuable as potential antibacterial agents against some plant pathogens.