In this study, 700 samples of dairy and its products were collected from Istanbul and Trakya region and the samples were analyzed for L. monocytogenes by using the reference methods. 20 samples of 700 were L. monocytogenes positive. The positive samples were confirmed by using PCR. Antibiotic susceptibility tests were applied to the positive samples by using 16 different kinds of antibiotic to expose the sensitivity profiles of the agents. Serotyping procedures were applied to the positive samples and all the agents were determined as L. monocytogenes serovar 4d. PCR confirmed samples were sequenced and specific DNA sequences of the agents were determined. Afterwards, Lineage groups of the positive samples were investigated and all the positive samples were exposed to be in Lineage I. The last step of our study was to compare our samples with the reference samples that are isolated from different origins which were belonged to same and different Lineages and to discuss all procedures that were applied in the study.