Introduction: To assess the validity of complete blood count (CBC) parameters in the diagnosis and prognosis of idiopathic sudden sensorineural hearing loss (ISSNHL) in geriatric patients. Material and Method: Sixty-two patients (women, 36; men, 26; mean age of all patients, 51 +/- 19 years) with ISSNHL were included in our study, and 49 healthy volunteers (women, 33; men, 16; mean age of all volunteers 48.6 +/- 16.2 years) with no history of audiologic complaints or diseases formed the control group. Subjects in both the control and study groups were further divided into two groups according to their ages (= 65 years). CBC results were evaluated. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were calculated. Results: NLR and PLR values in patients diagnosed with sudden hearing loss were much higher compared to those in the control group. However, in geriatric patients, there was no difference in NLR and PLR between the study and control groups. There was also no difference in mean platelet volume (MPV) levels between the control and study groups at all ages. Red cell distribution width (RDW) was higher in both geriatric and non-geriatric patients with ISSNHL compared with the control group. When NLR, LPR, MPV, and RDW of patients with ISSNHL were compared between those who responded and those who did not respond to the standard treatment, there was no significant difference between the groups. Conclusion: NLR, PLR, and RDW are increased in ISSNHL patients aged <65 years but only RDW is increased in geriatric patients with ISSNHL
