AbstractAimsResidual abscess is a major complication after emergency surgery for gastroduodenal (GD) perforation. However, there is little evidence regarding potential risk factors contributing to its development. Establishing a risk stratification strategy would be valuable for the entire management process.MethodsThis single‐center, retrospective study analyzed 115 consecutive patients who underwent surgery for GD perforation between 2010 and 2023 at a secondary emergency care hospital. Patients were divided into two groups based on the presence or absence of residual abscesses. Potential risk factors for abscess formation were evaluated from various aspects.ResultsThe incidence of residual abscesses was 19.1% (22 of 115). Multivariable analysis revealed that current use of nonsteroidal antiinflammatory drugs (odds ratio [OR] 3.76, p = 0.037), cancer chemotherapy (OR 13.56, p = 0.005), and preoperative renal dysfunction (OR 4.72, p = 0.018) were independent predictors. A potential scoring model could be created using these three parameters, and the number of risk factors correlated with the likelihood of developing a residual abscess (0 vs. 1 vs. ≥2; 6.2% vs. 29.4% vs. 50.0%, p < 0.001). From a bacteriological point of view, the presence of Enterococcus in the ascites culture was closely related to its occurrence with 100% probability. Moreover, regarding early detection of this complication, C‐reactive protein on postoperative d 5 had the highest predictive ability with an area under the curve of 0.818.ConclusionThe risk of residual abscess formation after surgical treatment of GD perforation can be assessed utilizing both preoperative and postoperative information.