This study examined the microbiological and physicochemical characteristics of raw chicken fillets that had been dipped in both conventional and probiotic yoghurt that included Lactobacillus Acidophilus La-5 and Bifidobacterium longum ATCC15707 and had been stored for eight days at 4°C. In this regard, samples of chicken breast fillets were subjected to sensory, chemical (pH, cooking loss percentage, and thiobarbituric acid reactive chemicals), and microbiological analysis (APC, E.coli, S.aureus, Campylobacter, and Salmonella count) during storage at 4±1ºC for 8 days. In comparison with control samples, the mean values of (APC, E. coli and S. aureus, counts, pH index, malondialdehyde value, and cooking loss percentage) in the chicken breast fillets treated with regular (RY) and probiotic yogurt (PY) at day 8 of storage, were (5.17±0.35 , 4.53±0.37 ; 1.57±0.32 , 1.33±0.27 and 1.54±0.55 , 1.29±0.25 log CFU/g ; 4.78±0.02 , 4.72±0.03 ; 1.25±0.05 , 0.89±0.02 and 49 ± 0.05 , 45 ± 0.05 ) respectively, that showing significant reduction (P < 0.05), particularly that treated with probiotic yogurt (PY) which considered the best group showed remarkable reduction in all values compared with other groups. In the current study, there were no counts of Salmonella or Campylobacter in the chicken fillet samples that were analyzed. The study's findings indicated that probiotics inhibited the development of microorganisms, enhanced the physicochemical quality, and extended the shelf life of chicken meat fillets during both storage and cooking. Therefore, it is recommended to use probiotics as one of the biological preservation systems for foods.