Objective To explore and analyze the relationship between preoperative neutrophil-to-lymphocyte ratio (NLR), lymph node metastasis and prognosis in elderly patients with rectal cancer. Methods 102 elderly patients who underwent radical resection of rectal cancer were postoperative pathologically confirmed as rectal cancer in the hospital from February 2019 to February 2020 were retrospectively collected as the research subjects. The clinical data of all patients were collected, the blood samples were collected and the neutrophil count and lymphocyte count were determined. And the NLR was calculated. With the NLR cutoff value of 3.96 as the grouping standard, 102 patients were divided into high NLR group (NLR>3.96, n=40) and low NLR group (NLR≤3.96, n=62). Clinicopathological data such as tumor anatomical location, tumor diameter and lymph node metastasis were compared among patients with different levels of NLR. All patients were followed up for 2 years, and the related factors affecting the prognosis of patients were analyzed.Results There were no statistical differences in clinicopathological parameters such as anatomical location, history of diabetes mellitus, history of hypertension, tumor diameter and tumor volume between high NLR group and low NLR group in elderly patients with rectal cancer (P>0.05). The proportions of patients with lymph node metastasis, distant metastasis and later TNM stage were more in high NLR group than those in low NLR group. The lymph node metastasis, distant metastasis and TNM staging were all related factors affecting NLR (P<0.05). Univariate analysis showed that survival rate was lower among patients with larger tumor diameter and tumor volume, lymph node metastasis, distant metastasis, later TNM stage and higher NLR level (P<0.05). Multivariate regression analysis showed that the presence of lymph node metastasis, later TNM stage and NLR higher than 3.96 were independent influencing factors for prognosis of elderly patients with rectal cancer (P<0.05). The median survival time of patients in high NLR group was 22 months, and the median survival time of patients in low NLR group was not reached at the end of follow-up. The survival rate of patients in high NLR group was significantly lower than that in low NLR group (P<0.05).Conclusion Preoperative NLR in elderly patients with rectal cancer is highly correlated with lymph node metastasis and prognosis. The higher the level of NLR, the greater the probability of lymph node metastasis and the worse the prognosis of patients, suggesting that NLR can be used as an important marker in predicting and evaluating the prognosis of elderly patients with rectal cancer