Conclusions. This study revealed two characteristic findings of the feeling of ear fullness (FEF) in acute sensorineural hearing loss (ASNHL). First, that the appearance of FEF was not associated with the auditory function on audiograms; and second, that the disappearance of FEF is clearly associated with the hearing prognosis. Objective. FEF appears frequently in patients with ASNHL. However, there are few reports on this symptom and its mechanism has yet to be clarified. So we tried to investigate the character of FEF in ASNHL. Patients and methods. In this study, observations were made during the period from the first medical examination to 2 months after obtaining a steady audiogram on 227 ears from unilateral ASNHL cases, and the relationship between FEF and the audiograms was analyzed. Results. The FEF prevalence at the first medical examination was about 80% for any audiogram shape or hearing threshold. Moreover, the better the hearing prognosis, the higher the improvement rate of FEF.