Abstract: OBJECTIVE To explore the factors associated with postoperative abdominal infection in patients undergoing radical resection of colon cancer. METHODS A case-control study design was adopted. Seventy-five patients with abdominal infections after radical resection of colon cancer admitted to the Tianjin Medical University Chu Hsien-I Memorial Hospital from Jan. 2021 to Dec. 2023 were enrolled as the infection group. Based on a 1∶1 individual matching, 75 patients who did not develop abdominal infections after colon cancer surgery during the same period were enrolled as the non-infection group. The characteristics of the pathogens causing abdominal infections were analyzed. Logistic regression analysis was conducted to investigate the factors associated with abdominal infections after radical resection of colon cancer. RESULTS In the infection group, 89 strains of pathogens were isolated. There were 61 cases of single bacterial infection and 14 cases of mixed infection. Gram-negative bacteria predominated, and Escherichia coli was the most common. Among gram-positive bacteria, Staphylococcus epidermidis was the main species. Fungi accounted for 6.74%. Logistic regression analysis showed that prolonged operation duration (OR=2.499, 95% CI: 1.327-4.707), open surgery (OR=3.228, 95% CI: 1.601-6.512), comorbid diabetes mellitus (OR=2.609, 95% CI: 1.261-5.399) and preoperative albumin <35 g/L (OR=2.821, 95% CI: 1.530-5.199) were risk factors for postoperative abdominal infection (all P<0.05). CONCLUSIONS After radical resection of colon cancer, abdominal infections are primarily caused by gram-negative bacteria, with E. coli being the most common. Open surgery, comorbid diabetes mellitus, preoperative hypoalbuminemia and prolonged surgical duration are risk factors for postoperative abdominal infections.