Abstract: Pathogenicity and histopathology of listeria monocytogene isolates (11) from raw milk in mice was done. Swiss albino mice (18-22 g) were used as experimental animals. All the isolates were pathogenic and caused mortality within 2 to 6 days after intraperitoneal injection. Reisolation of the microorganism from different organs was done. Pathological changes in the liver, spleen, brain, kidneys and intestines were recorded.