Objective To evaluate the predictive value of the Model for End-Stage Liver Disease Excluding International Normalized Ratio （MELD-XI） score for long-term all-cause mortality in elderly patients after cardiac valve surgery. Methods This retrospective study incorporated 263 elderly patients （aged ≥ 65 years） who underwent cardiac valve surgery at the hospital between January and December 2013. The MELD-XI score was computed based on the preoperative levels of total bilirubin and serum creatinine， and the long-term survival status was acquired. Patients were classified into a low-score group （≤ 11.82） and a high-score group （> 11.82） according to the optimal cut-off value determined by receiver operating characteristic curve analysis. Univariate and multivariate Cox proportional hazards regression models were employed to analyze the association between the MELD-XI score and long-term mortality， which was validated by Kaplan-Meier survival curves and subgroup analysis. Results Over a median follow-up period of 7.9 years， 60 patients passed away. Multivariate Cox regression analysis indicated that for every 1-point increment in the MELD-XI score， there was a 9% rise in the mortality risk （HR = 1.09， 95%CI： 1.03 - 1.16， P = 0.002 4）. The high-score group exhibited a significantly greater mortality risk when compared to the low-score group （HR = 2.36， 95%CI： 1.29 - 4.35， P = 0.005 6）. Subgroup analysis revealed a consistent predictive value among patients with different clinical characteristics （all interaction P-values > 0.05）. Kaplan-Meier survival curves verified a significantly higher cumulative mortality in the high-score group （Log-rank P = 0.000 52）. Conclusion The preoperative MELD-XI score serves as an independent predictor of the long-term mortality risk in elderly patients following cardiac valve surgery， where higher scores are indicative of a poorer prognosis.