ABSTRACTPrecooked homogenized crawfish tail meat was inoculated withListeria monocytogenes,treated with lactic acid, and packaged in various atmospheres for D value determinations at 60C. D60values using 0.0, 0.5, 0.75, and 1.0% lactic acid (LA) treated meat were 4.68, 4.41, 3.46, and 2.49 min, respectively. LA increased sensitivity ofL. monocytogenesto heat but this was not solely due to a reduction of pH. Sensory analyses of odor, color, taste, and texture of uninoculated whole crawfish tail meat demonstrated no significant differences (P>0.05) between LA treated samples and controls. D60values for the bacterium in crawfish tail meat homogenate packed in air, O2, CO2, or N2were 10.58, 9.22, 11.68, or 12.97 min, respectively, which were not significantly different (P>0.05). When 1% LA was added, significant decreases (P0.05) D60values for crawfish tail meat treated with 1% LA and packed in air, O2, CO2, or N2were 3.44, 3.88, 3.48, or 3.08, respectively. These results show that heat treatments of 60C were lethal toL. monocytogenesin packaged crawfish tail meat homogenate regardless of package atmosphere. Additionally, LA increased the lethality of heat to the bacterium in all tested package atmospheres.