In recent years, food safety issues are health care intention because of the number of infected people and outbreak scale. One of the causes of food poisoning by microorganism is Listeria monocytogenes bacteria. Quick and accurate diagnosis of pathogens causing food poisoning will help the treatment and prevention of food insecurity. In this study, PCR techniques have been designed, applied to detect Listeria monocytogenes in foods. Results showed that PCR was able to detect sample contamination by Listeria monocytogenes at concentration of 10 exponent 2 cfu/mL. Compared with culture techniques, PCR has a sensitivity of 100 percent, a specificity of 75 percent. With the advantages of PCR are short time to conduct, high accuracy, high specificity, this technique can be applied in practice.