This study was carried out to determine the antibacterial activity of some plant extracts include :  Rosmarinus officinalis, Citrus sinensis, Eucalyptus globulus,  Psidium guajava, Matricaria chamomilla, Allium cepa,  Allium sativum and Nigella sativa . These extracts prepared by four solvents ( water – methanol – ethanol – acetone ) at different concentrations ( 100 , 200 , 400 mg / ml ) against pathogenic bacteria such as :  Escherichia coli,  Salmonella spp, Shigella flexneri, Enterobacter sakazakii, Staphylococcus aureus and Bacillus cereus. The antibacterial activity assessed by agar well diffusion method to evaluate inhibition of zone and also determine minimum inhibitory concentration ( MIC ) and minimum bactericidal concentration ( MBC ) by using serial dilution method . The results showed that the extracts of Rosmarinus officinalis, Citrus sinensis, Eucalyptus globulus, Psidium guajava exhibited the higher zones of inhibition against all pathogenic bacteria while Salmonella sppwas resistance to both the aqueous and ethanol extract of Rosmarinus officinalis and resistance to the aqueous extract of Eucalyptus globulus and Psidium guajava. Matricaria chamomilla showed moderate antibacterial effects except  Salmonella spp was resistance to the ethanol extract while Allium cepa and Allium sativum showed lower antibacterial activity. Nigella sativa showed no antibacterial activity against all pathogenic bacteria. Respect to MIC and MBC of the Rosmarinus officinalis, the aqueous extract was 25 mg / ml for all bacteria,  the methanol extract showed MIC ( 6.25 mg / ml ) and MBC ( 12.5 mg / ml ) for Escherichia coli, Salmonella spp, Staphylococcus aureus and Bacillus cereus also MIC was ( 12.5 mg /ml ) and MBC ( 25 mg / ml ) for Enterobacter sakazakii and Shigella flexneri. Ethanol extract showed MIC ( 6.25 mg / ml ) and MBC ( 12.5 mg / ml ) for Escherichia coli and Staphylococcus aureus while MIC was ( 12.5 mg / ml ) and MBC was ( 25 mg / ml ) for Shigella flexneri and Bacillus cereus but MIC and MBC were ( < 25 mg / ml ) for Enterobacter sakazakii . The acetone extract showed MIC at ( 6.25 mg / ml ) and MBC at ( 12.5 mg / ml ) for Salmonella spp and Enterobacter sakazakii respectively. MIC was ( 12.5 mg / ml ) and MBC was ( 25 mg / ml ) for Escherichia coli,  Staphylococcus aureus and Shigella flexneri while MIC was ( 25 mg / ml ) and MBC was ( < 25 mg / ml ). The other plant extracts showed MIC and MBC
( <  25 mg / ml ) for all tested pathogenic bacteria .