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Background and Objective: Listeria monocytogenes is a gram-positive facultative intracellular non spore forming bacillus. The epidemiologic studies have shown that Listeria monocytogenes is the cause of abortion and abnormalities in human embryo. This study was done to determine the effect of listeria monocytogenes colonization on maternal and fetal liver and spleen in mice. Methods: In this experimental study, Inbred BALB/c dams allocated into case and control groups. Dams in interventional and control groups were received 200µL of 1.2 LogFCU/ml, Listeria monocytogenes and normal salin intraperitoneally, respectively. Few mice from each group were randomally selected and 5ml of blood collected, placenta, uterus liver and spleen were removed subsequently in 13 and 24 day of gestation and listeria monocytogenes colonization were determined. Liver and spleen of full term offsprings were stained for the histological studies. Results: L.monocytogenes strains were detected in different organs of mice damsup for 30 day of gestation. The higest and lowest of organ contamination were seen in liver and blood samples, respectively. The ratio of weight/volume of organ was higher in case than control groups. Hepatocytes degenration, hepatocyte size alteration, cell cord atrophy and sinusoid dilatation were seen in the liver. Disruption of red pulp, disorganization of lymphoid nodules and necrosis were noticed in the spleen. Conclusion: Contamination of BALB/c dams causes the histological alterations in the liver and spleen of offesprings.