Objective To investigate the application value of prognostic nutritional index and urea/creatinine ratio in nutritional status assessment for patients with esophageal cancer undergoing radiotherapy and chemotherapy. Methods A total of 138 patients with esophageal cancer who received radiotherapy and chemotherapy were screened. NRS 2002 nutritional screening was used as the standard. Prognostic nutritional index （PNI） and urea/creatinine ratio （UCR） were used to evaluate the malnutrition of patients with esophageal cancer. ROC curve was used to evaluate and compare the diagnostic efficacy of different nutritional screening tools. Results The biochemical and hematological indexes of patients with esophageal cancer showed certain characteristics， in which the levels of urea， creatinine， UCR， ALB， PALB， TP， TC， TG， HDL and LDL all fluctuated within the normal range. In terms of nutritional risk screening， the NRS 2002 score identified nutritional risk in 57.97% of patients， while the PNI and UCR predicted nutritional risk in 31.16% and 40.58% of patients， respectively. Consistency test showed that the Kappa value of PNI and NRS 2002 scores was 0.460 （P < 0.05）， and the Kappa value of UCR and NRS 2002 scores was 0.522 （P < 0.05）， indicating that there was a certain correlation between them and NRS 2002 scores in nutritional risk screening. Correlation analysis showed that NRS 2002 score was significantly correlated with UCR， ALB， PALB， PBL， Cr， HDL and TP （P < 0.05）， while PNI was significantly correlated with ALB， PALB， PBL， Cr， HDL， TP and UREA （P < 0.05）. There were significant correlations between UCR and PALB， UREA and Cr （P < 0.05）. Logistic univariate regression analysis further confirmed these correlations and revealed that malnutrition was negatively correlated with albumin， prealbumin， total protein， lymphocytes， creatinine and BMI， and positively correlated with urea. However， multivariate regression analysis did not find any statistical difference between these related factors and the two objective evaluation measures. The results of diagnostic efficacy evaluation showed that the area under ROC curve of PNI and UCR evaluation to predict esophageal cancer malnutrition was 0.779 and 0.736， respectively， with statistical significance （P < 0.001）. Among them， UCR showed higher sensitivity and PNI showed higher specificity， but there was no significant difference in diagnostic value between them. Conclusion PNI and UCR as nutritional assessment tools have certain application value in the nutritional risk screening of patients with esophageal cancer， but their consistency with NRS 2002 score needs to be improved. When assessing the nutritional status of patients， a combination of various indicators and methods should be used to achieve more accurate diagnostic results.