Sudden hearing loss (SHL) is a significant problem requiring emergency intervention; however, consensus on its diagnosis and treatment remains to be determined. Although several factors could cause SHL, its cause can only be determined in 10% of patients. Several approaches have been described for its treatment. The primary aim of treatment is to prevent cochlear hypoxia by increasing the partial O2 pressure in the perilymph. Apelin is an oxidative stress mediator. If apelin level changes are associated with SHL etiology, the protective and therapeutic effects of apelin can be beneficial. This study aimed to investigate the extent of influence of apelin hormone level changes in the SHL etiology. A total of 27 patients diagnosed with SHL and 26 healthy volunteers were evaluated as the patient and control groups, respectively. Apelin levels, biochemical parameters, and hemoglobin levels were measured. No difference was found between the patient and control groups in respect of apelin and other parameters. Although the study results did not show a statistically significant difference, the degree of hearing loss increased with decreased apelin levels in patients with SHL. Although not statistically significant, Apelin level was lower as the level of hearing loss increased in patients presenting with SHL. According to studies, it can be thought that patients with low apelin levels can be assumed to be less likely protected against inflammatory diseases related to oxidative stress. Therefore, further comprehensive and extensive clinical studies to examine apelin effect mechanisms should be performed. According to studies, the Apelin hormone shows a protective effect against inflammatory diseases caused by oxidative stress. In our study, there was no significant difference when Apelin hormone levels were compared with the patients with sudden hearing loss in the control group. However, due to the low number of patients to investigate the mechanisms of action of Apelin, more extensive and larger studies are needed.