Listeria monocytogenes is of great concern to the food industry, especially in foods stored under refrigerated conditions where, unlike most food-borne pathogens, L. monocytogenes is able to multiply so this investigation was conducted to study the inhibitory effect of some spice extracts namely thyme, sumac and black pepper commonly used in food Assiut Vet. Med. J. Vol. 52 No. 110 July 2006 industry on the growth of this pathogen. Three different concentrations (2.5, 5 and 10%) of the spice extracts were used. Two different procedures were carried out to evaluate the inhibitory effect of these spice extracts, agar cup method and food model. In, agar cup method, the obtained results showed that the lowest concentration which produced inhibitory effect on the growth of this pathogen with inhibition zone of 15mm were of sumac and thyme 2.5%. In the second procedure on food model (minced meat) stored at 3 °C for 7 days, the results revealed that the lowest concentration which exhibited a great decline in counts of L. monocytogenes after 7 days of storage by log 1.9 cfu/g was sumac 5% (in comparison to control).