Objective To explore the impact of pre -treatment nutritional status on the outcome of elderly patients with locally advanced esophageal squamous cell carcinoma undergoing radical radiotherapy. Method A total of 96 elderly patients with locally advanced esophageal squamous cell carcinoma who received treatment at Jiangsu Cancer Hospital from May 2021 to January 2023 were selected. Prior to treatment levels of prealbumin PAB hemoglobin Hb serum albumin ALB and NRS 2002 score were tested and binary logistic regression analysis was performed to determine the prognostic factors affecting the patients. According to the patient′s prognosis they were further divided into two groups namely the poor prognosis group death n = 32 and the good prognosis group survival n = 64 . The levels of PAB Hb ALB and NRS 2002 scores were compared between the two groups. Analyze the predictive value of PAB Hb ALB levels and NRS 2002 score values through ROC curve analysis. Result 96 patients underwent serum tests before treatment with ALB 43. 86 ± 9. 86 g / L PAB 178. 95 ± 18. 53 mg / L Hb 129. 84 ± 15. 43 g / L and NRS 2002 3. 49 ± 1. 86 points. According to binary logistic regression analysis pre-treatment ALB ≤ 44g / L pre-treatment PAB ≤ 179 mg / L pre-treatment Hb ≤ 126 g / L and pre-treatment NRS 2002 score>3 points are prognostic factors affecting elderly patients with locally advanced esophageal squamous cell carcinoma P<0. 05 . The regression model was validated using Bootstrap method with an AUC of 0. 866 and 95%CI = 0. 795-0. 938. Meanwhile the ALB 52. 65 ± 8. 91 g / L PAB 189. 63 ± 19. 12 mg / L and Hb 141. 58 ± 17. 21 g / L in the group with good prognosis were higher than those in the group with poor prognosis and the NRS 2002 score 1. 55 ± 0. 75 was lower than that in the group with poor prognosis P<0. 05 . Through ROC analysis the ALB PAB Hb and NRS 2002 scores predicted the prognosis of elderly patients with locally advanced esophageal squamous cell carcinoma to be 0. 836 0. 898 0. 877 and 0. 914 respectively. Conclusion PAB Hb ALB levels and NRS 2002 score value can predict the survival prognosis of elderly patients with locally advanced esophageal squamous cell carcinoma. By testing their nutritional status before treatment it can play an important role in the recent efficacy and survival prognosis which is conducive to reducing mortality and improving prognosis.