Objective To investigate the contamination of Listeria monocytogenes (LM) in ready-to-eat (RTE) food in Chongqing and make a preliminary risk assessment, which would provide scientific basis for the prevention. To investigate the contamination of Listeria monocytogenes (LM) in ready-to-eat (RTE) food in Chongqing and make a preliminary risk assessment, which would provide scientific basis for the prevention.Methods Two thousand six hundred and eighty food samples were collected from 39 districts and counties of Chongqing and LM testing was carried out according to the national standard. A risk ranger tool was used to make preliminary risk asseeement for LM in RTE food. 2680 food samples were collected from 39 districts and counties of Chongqing and LM testing was carried out according to the national standard. A Risk Ranger tool was used to make preliminary risk asseeement for LM in RTE food.Results The prevalence of LM in RTE food was 1.77%. The detection rate of LM in Chinese cold dishes was higher than that in cooked meat products, raw aquatic products and RTE bean products (P<0.05). The detection rate of LM in supermarkets, restaurants, farmer's markets and convenience stores were about the same (P>0.05). The peak season of LM contamination was the fourth season (P>0.05). In the form of packaging, contamination mainly came from bulk food (P<0.05). In Chongqing, the annual incidence of listeriosis caused by consumption of cooked meat products, Chinese cold dishes, raw aquatic products and RTE bean products was estimated to be 633.7 cases, 134.7 cases, 2.4 cases and 31.5 cases per million population respectively. The prevalence of LM in RTE food was 1.77. The detection rate of LM in Chinese cold dishes was higher than that in cooked meat products, raw aquatic products and RTE bean products (P<0.05). The detection rate of LM in supermarkets, restaurants, farmer's markets and convenience stores were about the same (P>0.05). The peak seasons of LM contamination was the fourth season (P>0.05). In the form of packaging, contamination mainly comes from bulk food (P<0.05). In Chongqing, the annual incidence of listeriosis caused by consumption of cooked meat products, Chinese cold dishes, raw aquatic products and RTE bean products is estimated to be 633.7 cases, 134.7 cases, 2.4 cases and 31.5 cases per million population respectively. Conclusion The surveillance data showed that LM were existed at different levels in RTE food in Chongqing. Preliminary risk assessment showed the LM risk of cooked meat products was relatively high. It is suggested that effective control and monitoring measures should be taken in the later stage of RTE food processing, and the quantitative risk assessment study of Listeria monocytogenes in cooked meat products and Chinese cold dishes should be given priority to reduce the potential harm. The surveillance data showed that LM were existed at different levels in RTE food in Chongqing. Preliminary risk assement showed the LM risk of cooked meat products was relatively high. It is suggested that effective control and monitoring measures should be taken in the later stage of RTE food processing, and the quantitative risk assessment study of Listeria monocytogenes in cooked meat products and Chinese cold dishes should be given priority to reduce the potential harm.