Listeria monocytogenes is an important food borne pathogen responsible for listeriosis, a fatal disease. It is widely distributed in various foods and environmental sources. This pathogen has been isolated from different food products, but milk products surely play a major role in the epidemiology of this food borne disease. More recently, molecular methods were developed that target RNA rather than DNA , such as RT -PCR, real time PCR or nucleic acid sequence-based amplification (NA SBA).In this review, the risk of L.monocytogenes illness associated to the consumption of RTE meat based foods Coimbatore city inhabitants appeared to be relatively low (ranging from 1.7 to 3.4% depending of the risk exposure pathway) and was found to be increasing with the meat consumption level in different socio-economical category of the consumers. And also was to develop a method combining nanoparticle-based immunomagnetic separation (IMS) with real-time PCR for a rapid and quantitative detection of Listeria monocytogenes. Carboxyl modified magnetic nanoparticles were covalently bound with rabbit antiL.monocytogenes via the amine groups. . Our results demonstrated that both the use of nanoparticles and the choice of anti- L.monocytogenes in our IMNP based IMS in combination with real time PCR has improved the sensitivity of L.monocytogenes d e t e ct ion .