A total of 400 samples were collected from 100 slaughtered carcasses (cattle, buffalo, sheep and goat, 25 of each). Four samples from each carcass representing: muscle, liver, kidney and heart were collected for detection of L. monocytogenes. Also, 100 environmental samples representing water used in abattoir, knife swabs and swabs from abattoir walls before and after cleaning, (25 for each) and 100 fecal swabs from abattoirs' workers were randomly collected from different abattoirs located at Dakahlia governorate, Egypt. The Prevalence rate of L. monocytogenes in cattle carcasses was 3 (12%), 2 (8%) and 1(4%) in examined liver, kidneys and heart samples out of 25 examined samples for each organ, respectively and couldn't be detected in any of muscle samples. Meanwhile, in buffalo carcasses, theprevalence rate was 4 (16%), 2 (8%),1 (4%) and 1 (4%) in examined liver, kidneys, heart and muscle samples out of 25  examined samples for each organ, respectively. Meanwhile, in sheep carcasses, the prevalence rate of L. monocytogenes was 3 (12%), 2 (8%), 2 (8%) and 2 (8%) in examined liver, kidneys, heart and muscle samples out of 25 examined samples for each organ, respectively. Meanwhile, in goat carcasses, the prevalence rate was 4 (12%), 2 (8%), 2 (8%) and 1(4%) in examined liver, kidneys, heart and muscle samples out of 25  examined samples for each organ, respectively. In environmental samples, the prevalence rate was 28% from examined wall swabs before cleaning, 4% from examined wall swabs after cleaning, 4% from examined knife swabs and 4% from fecal swabs from abattoirs workers. Meanwhile, no L. monocytogenes was detected in water samples. Regarding pathogenicity test, death of all inoculated wining rabbits (23) as following 60% on 3^rd day, 30% on 4^th day and 10% on 5^th day and                L. monocytogenes was isolated from their organs. The isolates of L. monocytogenes were found to be virulent by using PCR assay incorporating inlA, hlyA and prfA genes primers. The public health hazards as well as suggestive measures to reduce human listeriosis have been discussed.