Objective To explore the risk factors of wound infection in elderly patients with open fractures. Methods A retrospective analysis was conducted on 160 elderly patients with open fractures admitted in our department from February 2022 to February 2024. Based on the occurrence of wound infection during hospitalization, they were divided into an infection group (n=34) and a non-infection group (n=126). The general demographic data, laboratory indicators, disease conditions and treatment-related data were collected and compared between the two groups. SPSS 26.0 was used for data analysis, and t test or χ² test was performed depending on data type. Binary logistic regression analysis was employed to identify the risk factors of wound infection in the patients. Results The incidence of wound infection was 21.25% (34/160) in the cohort. Bacterial culture of wound secretion in the 34 infectious patients revealed that 28 cases (82.4%) were positive for bacterial culture. There were 28 strains of pathogenic bacteria detected, including 15 strains of Staphylococcus aureus (53.57%), 7 strains of Pseudomonas aeruginosa (25.00%), 4 strains of Escherichia coli (14.29%), and 2 strains of Acinetobacter baumannii (7.14%). Taking presence or absence of wound infection in elderly patients with open fractures during hospitalization as the dependent variable, binary logistic regression analysis showed that diabetes mellitus (OR=3.442, 95%CI 1.254-9.444), hypertension (OR=3.065, 95%CI 1.583-5.933) and Gustilo-Anderson type Ⅲ (OR=7.367, 95%CI 1.711-31.728) were independent risk factors for infection in elderly patients with open fractures, and the time from injury to first debridement <3 h (OR=0.838, 95%CI 0.761-0.922) was a protective factor (P<0.05). Conclusion Diabetes mellitus, hypertension, Gustilo-Anderson type, and time from injury to first debridement are influencing factors of wound infection in elderly patients with open fractures.