Objectives: To investigate the correlation between glomerular filtration rate (GFR) and sudden deafness, and to analyze the prognostic factors of sudden deafness. Methods: (1) To retrospectively analyze 261 cases of sudden deafness with complete clinical data who were hospitalized in the Department of Otolaryngology of our hospital from January 2021 to October 2022, and compare the eGFR levels of sudden deafness patients with different clinical characteristics; (2) The influencing factors of the prognosis of sudden deafness were analyzed and the ROC curve was drawn to evaluate the predictive efficiency. Results: (1) Hearing values (dB) of patients with sudden deafness were linearly and negatively correlated with eGFR levels (P=0.02). (2) The level of eGFR was associated with gender, age, hypertension, diabetes, smoking and type of hearing loss of patients with sudden deafness (all P<0.05). (3) The eGFR level and hearing loss type were independent influencing factors for the prognosis of sudden deafness (P<0.05) (4) The area under the ROC curve of eGFR was 0.704 (95%CI:0.642-0.766), and the prediction model was statistically significant (P<0.001), when the Youden index was 0.360, the optimal decision threshold was 103.50 ml·min-1·1.73m-2. Conclusion(s): (1) The level of eGFR is related to the patient's gender, age, history of hypertension, history of diabetes, history of smoking and type of hearing loss. (2) The level of eGFR and type of hearing loss are independent factors influencing the prognosis of sudden deafness.