Listeria monocytogenes is a deadly foodborne pathogen, which is found in the environment, soil, animal and human feces, sewage, and water. It can be transmitted to ready-to-eat foods after cooking because of cross-contamination from the post-processing environment (during slicing and packaging). This microorganism can multiply in meats in vacuum packages at refrigerator temperatures and those consumed without re-heating, which is a great concern in refrigerated foods with extended shelf lives. In this study, two types of ham (one natural and one with added Listeria inhibitors) were inoculated with a cocktail of nine serotypes of L. monocytogenes and examined on days 0, 1, 3, 7, 14, 21 and 28. The effects of three different combinations of treatments of lactic acid bacteria and one of water with a control group were compared. All of the lactic acid bacteria (LAB) treatments exhibited inhibitory effects on the growth of L. monocytogenes during storage. The L. monocytogenes in the natural ham increased during storage but when LAB were added, there was about 1.6 to 2 log cycle reduction of growth at the end of the storage period. In the ham with added Potassium lactate, the number of L. monocytogenes in the control group was significantly higher than in the LAB treated groups. In conclusion, the use of LAB to inhibit L. monocytogenes is effective in controlling the growth of the pathogen over time. The impact is greater in natural products without preservatives. Carefully selecting particular strains of LAB is critical to ensure that the maximum inhibition is observed.