Corticosteroid treatment has been considered the most effective treatment modality for sudden sensorineural hearing loss so far. Application route of corticosteroids may vary. We have designed a prospective randomized case-controlled clinical trial to evaluate the effectivenesses of the different application routes of steroids in the treatment of SSHL. Thirty-five patients were distributed randomly to two groups which were treated with either 'oral' or 'intratympanic' corticosteroids. Intratympanic steroid administration was performed three times every other day transtympanically. At the end of third month, recovery rate in the 'intratympanic' group was 84.2%, whereas in the 'oral' group, it was 87.5%. The difference between the recovery rates was not statistically significant. There were no major complications related to transtympanic steroid administration. These findings support that intratympanic steroid therapy is an alternative to systemic steroid therapy in the initial treatment of sudden hearing loss. In addition, transtympanic technique is an easy to perform and safe method for delivering steroids into the inner ear.