Abstract: OBJECTIVE To explore the risk factors for postoperative nosocomial infection in the acute myocardial infarction（AMI） patients undergoing percutaneous coronary intervention（PCI）.METHODS From May 2018 to Sep 2020, a total of 54 AMI patients who were treated in Wuzhou Workers’ Hospital and had postoperative nosocomial infection were assigned as the infection group, meanwhile, 54 patients who did not have nosocomial infection, in a 1:1 ratio case control, were set as the control group. Univariate analysis and multivariate logistic regression analysis were performed for risk factors for the postoperative nosocomial infection in the PCI patients.RESULTS Among the 54 AMI patients with postoperative nosocomial infection, the patients with respiratory tract infection accounted for 52.85%, and the patients with urinary system infection accounted for 20.37%. Totally 76 strains of pathogens were isolated and identified, 51（67.11%） of which were gram-negative bacteria, 18（23.68%） were gram-positive bacteria; Klebsiella pneumoniae and Pseudomonas aeruginosa were dominant among the gram-negative bacteria, accounting for 25.00% and 22.37%, respectively; Staphylococcus aureus was the predominant species of gram-positive bacteria, accounting for 10.53%. Univariate analysis indicated that the postoperative nosocomial infection in the AMI patients was associated with the age, complication with diabetes mellitus, grade of cardiac function, arrhythmia, prophylactic use of antibiotics, mechanical ventilation, urinary catheter indwelling and length of hospital stay（P＜0.05）. Multivariate logistic regression analysis showed that the no less than 60 years of age, complication with diabetes mellitus, mechanical ventilation, urinary catheter indwelling and length of hospital no less than 14 days were the independent risk factors for the postoperative nosocomial infection in the AMI patients（P＜0.05）.CONCLUSION The gram-negative bacteria are dominant among the pathogens causing the postoperative nosocomial infection in the AMI patients, and the risk of infection can be affected by the age, complication with diabetes mellitus, mechanical ventilation, urinary catheter indwelling and length of hospital stay.