Eighteen cases of idiopathic sudden hearing loss were evaluated in clinical point of view. No age, sex and site difference were seen in these cases. It was developed most frequently in February(5 cases), and noticed most commonly at the time of awakening in the morning. In seven cases, common cold was associated with the development of the hearing loss. Accompanying symptoms were tinnitus(16 cases), vertigo(12 cases), ear fullness(10 cases), and headache(13 cases). The therapeutic results were 5 cases of complete recovery, 5 cases of partial recovery, 3 cases of slight improvement, and 5 cases of no improvement. Those patients who were admitted within 7 days from onset, and who had no associated vertigo revealed better recovery rate.