Nowadays, all interested parties in the field of food safety are shifted to use natural food preservatives instead of chemical ones which proved to have many draw backs either on human health or food composition. The present study was conducted to study the effect of using two probiotic strains (Lactobacillus acidophilus and Bifidobacteriumlactis) individually on the growth and survival of some food-borne pathogens represented by Staphylococcus aureus and Escherichia coli experimentally inoculated separately into fresh minced beef, previously gamma irradiated using 5 KGy to be sure that samples were free from microorganisms under investigation during storage at 4°C.The obtained results revealed that the effect of Lactobacillus acidophilus on the reduction of Staph.aureus count was almost identical to the effect of Bifidobacteriumlactis. Moreover, Staph.aureus growth persisted till the 6th day of storage, while the organism was completely inhibited at the 8th day of the experiment. Bifidobacteriumlactis was more effective in reducing E. coli count through the 8 days of experimental study than Lactobacillus acidophilus. Overall, E. coli could persist till the end of the experimental period in the presence of both probiotics. The maximum reduction % of E. coli count reached 2.0 log10cfu/g (46.95%) in experimental samples using Bifidobacteriumlactis.