Abstract: OBJECTIVE To explore the incidence of postoperative health care-associated infections (HAIs) in the colostomy patients and analyze the pathogens and risk factors. METHODS A total of 528 patients who underwent colostomy in gastrointestinal surgery department of Hangzhou First People's Hospital, Affiliated School of Medicine, Westlake University from Jan. 2022 to Dec. 2024 were recruited as the research subjects and were divided into the infection group with 136 cases and the non-infection group according to the status of postoperative HAIs. The postoperative infection sites and distribution of pathogens were observed. Multivariate logistic regression analysis was performed for the risk factors. RESULTS Totally 136 (25.76%) patients had postoperative infections, 102 (75.00%) of whom had surgical site infections, including 52 (38.24%) patients with superficial incision infections, 31 (22.79%) patients with deep incision infections, and 19 (13.97%) patients with organ/space infections. A total of 162 strains of pathogens were isolated, among which gram-negative bacteria accounted for 61.11%, gram-positive bacteria accounted for 27.78%; Escherichia coli (30.25%) and Klebsiella pneumoniae (17.28%) were the predominant species of the gram-negative bacteria; Staphylococcus aureus (14.81%) was dominant among the gram-positive bacteria; all of the fungal strains were Candida albicans (11.11%). Multivariate analysis showed that complication with diabetes mellitus(OR=3.010), operation duration more than 180 min (OR=2.260), hypoproteinemia (OR=2.612), drainage tube indwelling more than 7 days (OR=1.819), anemia (OR=2.126) and the time to first postoperative ambulation more than 3 days(OR=1.527) were the risk factors for the postoperative HAIs in the colostomy patients (all P＜0.05). CONCLUSIONS The incidence of postoperative HAIs is high among the colostomy patients, which is closely associated with the underlying disease, state of nutrition, surgical trauma and postoperative management. It is an effective way to take comprehensive prevention strategies targeting the risk factors so as to reduce the incidence of infections and improve the prognosis.