ObjectiveTo explore risk factors for hospitalacquired pneumonia (HAP) and ventilatorassociated pneumonia (VAP) in patients undergoing emergency surgery, provide evidence for reducing the incidence of healthcareassociated infection(HAI).MethodsClinical data of patients undergoing emergency and selective surgery in a hospital from January 2014 to December 2016 were surveyed retrospectively, incidence and distribution of pathogens of HAP and VAP after surgery were analyzed, risk factors for HAP and VAP in patients undergoing emergency surgery were analyzed.ResultsA total of 3 526 patients who underwent emergency surgery were selected, 123 cases of HAI occurred, HAI case rate was 3.49%; 55 cases of HAP and 20 cases of VAP occurred among patients undergoing emergency surgery. 6 904 patients underwent selective surgery, 192 cases of HAI occurred, HAI case rate was 2.78%； 53 cases of HAP and 17 cases of VAP occurred among patients undergoing selective surgery; HAI case rate, incidences of HAP and VAP in the emergency surgery were all higher than those of selective surgery, difference were all statistically significant (all P<0.05). Gramnegative bacteria were the main pathogens isolated from patients with HAP and VAP after surgery. Sex (male), age (≥60 years), coma, tracheotomy/tracheal intubation, mechanical ventilation, combined use of antimicrobial agents, oral care, history of staying in ICU, and the number of surgery≥2 times were independent risk factors for HAP in patients undergoing emergency surgery (all P<0.05); coma and the number of surgery≥2 times were independent risk factors for VAP in patients undergoing emergency surgery (both P<0.05).ConclusionIncidences of HAP and VAP are higher in patients undergoing emergency surgery, each has its own independent risk factors, targeted prevention and control measures should be taken according to the relevant risk factors.