Objective To explore the clinical characteristics and prognostic risk factors for elderly patients with sepsis. Methods The elderly patients with sepsis treated in a tertiary first-class hospital from July 2020 to September 2021 were selected, clinical and laboratory data of patients were recorded, patients were divided into survival group and death group according to 28-day prognosis, differences in clinical indicators between two groups were compared, independent risk factors for prognosis of elderly patients with sepsis were analyzed by binary logistic regression analysis, receiver operating characteristic curve(ROC) was drawn to evaluate the effect of different indicators on predicting the prognosis of patients. Results A total of 121 patients were included in analysis, including 74 cases of sepsis and 47 cases of septic shock. 92 patients were in survival group and 29 in death group. Compared with the survival group, the proportion of septic shock and the number of complications ≥2 in death group was higher (P < 0.05); the scores of sequential organ failure assessment(SOFA)and acute physiology and chronic health evaluation (APACHE Ⅱ) were higher, the expression levels of interleukin 6(IL-6), cystatin C (Cys-C), procalcitonin (PCT), prothrombin time (PT), and D-dimer (D -D) all enhanced (all P < 0.05), while expression level of absolute lymphocyte count (ALC) and expression of albumin (ALB) dropped (both P < 0.01). Binary logistic regression analysis showed that septic shock, SOFA score, D -D and expression of Cys-C were independent risk factors affecting the 28-day prognosis of elderly patients with sepsis. ROC curve analysis showed that SOFA score (AUC=0.758), D -D (AUC=0.774) and Cys-C (AUC=0.650) had a certain value for the prediction of prognosis of patients (all P < 0.01), compared with a single indicator, the combined detection of three indicators showed a higher predictive value (AUC=0.882). Conclusion Occurrence of septic shock, increase of SOFA score as well as enhanced expression of D -D and Cys-C are independent risk factors leading to the increase of mortality in elderly patients with sepsis. The combined detection of SOFA score, D -D and Cys-C can further improve the predictive value of prognosis in patients with sepsis, and provide reference basis for clinical treatment and prognosis evaluation.