Abstract: This study was conducted to determine the effects of some plant essential oils on B. cereus, S. typhimurium, L. monocytogenes and Y. enterocolitica. In the first step Minimum Inhibitory Concentration (MIC) and Minimum Bacteriocidal Concentration (MBC) of plant essential oils were determined by Tube Dilution Method in Luria-Bertani broth medium. In the second step the growth rate of each bacterium was assessed in presence of plant essential oils in concentration of less than MIC. The results showed that the essential oils of the plants used in this study have the acceptable antimicrobial activities against tested bacteria, the Caraway seed oils showed the most antimicrobial activity followed by Pennyroyal and Peppermint but Tarragon oils showed the least antimicrobial activity on tested bacteria. The results of the second step showed that, the plant essential oils were affected not only on lag phase but also on logarithmic phase of growth of bacteria.