Food manufacturers and consumers demand additive-free, fresh and full- tasting food products while maintaining high standards of microbiological safety. The use of natural antimicrobial system for the preservation of foods could satisfy this demand. The use of certain plant extracts can guarantee a good microbiological safety in foods. There is a little quantitative data on antimicrobial activity of most plants extracts. Therefore, the growth of eleven food borne pathogenic bacterial strains: four Gram negative (Enferobacfer (Ent) aerogenes, Escherichia (E.) coir, Pseudomonas (Pa) aeruginosa and PS. fluorescens) and seven Gram-positive (Bacillus (B) careus, B. firmus. B. pumri'us, B. subtriis, Micrococcus (M ) Iuteus, M van'ans and Staphylococcus (5.) aureus) was studied in liquid media in the presence of some plant extracts (water and ethanolic) rich in total phenolic compounds, namely black tea, grape seed, green tea, rosemary and reference compounds (caffeine and catechin). The ethanolic extracts of black tea, grape seed, green tea, and rosemary appear to be promising antibacterial agents and could be used in food industry to guarantee a good microbiological safety of foods.