Listeria monocytogenes ( LM) is an important pathogen causing bacteremia and meningoencephalitis among newborns, pregnant women, the elderly, and immunosuppressed patients. Low incidence but high mortality characterizes a bloodstreaminfection caused by LM. Isolation and identification of LMare not easy in the clinical microbiology laboratory. In the present paper, acase of LM blood infection is presented, whichwas diagnosed rapidly by amplifying prfA gene through polymerase chain reaction in addition to traditional microbiological assays.