Abstract: OBJECTIVE To explore the related factors for mediastinal infections in patients after cardiac surgery so as to provide guidance for prevention and treatment of infections. METHODS A total of 233 patients who received cardiac surgery in the hospital from Jan 2012 to Dec 2016 were recruited as the study objects, the prevalence of postoperative mediastinal infections was investigated, the related factors for the infections were statistically analyzed, and the distribution of pathogens isolated from the patients with mediastinal infections was observed. RESULTS Of the 233 patients who received the cardiac surgery, 11 had postoperative mediastinal infections, with the infections rate 4.72%.The multivariate logistic regression analysis indicated that the incidence of mediastinal infections was positively correlated with the advanced age, diabetes mellitus, hyperlipidemia, open drug dressing and blood circulation disorder, which were the influencing factors for the mediastinal infections.Totally 18 strains of pathogens were isolated from the 11 patient with infections, of which 8 (44.44%) were gram-negative bacteria, and 10 (55.56%) were gram-positive bacteria; Pseudomonas aeruginosa was the predominant species of the gram-negative bacteria; Enterococcus was dominant among the gram-positive bacteria. CONCLUSION The prevalence of the postoperative mediastinal infections is high among the patients undergoing the cardiac surgery, there are a variety of related factors for the infections.It is necessary to carry out the early diagnosis and treatment according to the related factors so as to reduce the incidence of postoperative mediastinal infections.