Background <p>The aim of this study was to discover immune-nutritional indicators that can preoperatively predict short-term mortality in older patients undergoing emergency gastrointestinal surgery.</p> Methods <p>We retrospectively analyzed older patients older than 65 years of age who underwent various types of emergency gastrointestinal surgery under general anesthesia between January 2012 and December 2023. The immune-nutritional indicators were defined according to previous literature. The primary endpoint of this study was 90-day survival after surgery.</p> Results <p>A total of 4120 patients older than 65 years were included in this study. ROC curves and the decision curve analysis for eight factors predicting 90-day postoperative survival were well predicted by the mGPS (0.68, 95% CI: 0.66–0.70), PNI (0.68, 95% CI: 0.66–0.71) and CONUT score (0.68, 95% CI: 0.66–0.70). The models constructed by LASSO Cox and CoxBoost were used to score the risk for each patient, and the high LASSO Cox model risk score group had worse 90-day survival than the low score group, whereas patients in the low CoxBoost model score group had a worse prognosis. The AUC of the CoxBoost model was greater than that of the LASSO Cox model. A nomogram model was constructed using the variables screened by the LASSO Cox model with a C-index of 0.706.</p> Conclusions <p>Immune-nutritional factors could be a favorable predictor for older patients undergoing emergency gastrointestinal surgery.</p>