Steroids are the only proven drugs in the treatment for idiopathic sudden sensorineural hearing loss. In the recent studies, it has been suggested that, steroids delivered through the intratympanic route obtained higher perilymph levels, resulting in better hearing outcomes. The purpose of this study is to compare the hearing outcomes of the two routes of steroid treatment: intratympanic route and systemic route. In this prospective study, 60 consecutive patients with idiopathic sensorineural hearing loss treated between January 2005 and September 2008 were enrolled: 29 were in the intratympanic steroid group (ITSG) and 31 were in the systemic steroid group (SSG). In the ITSG, 5 intratympanic injections of dexamethasone were performed with the dose of 4 mg/ml, consecutively. Oral methylprednisolone was given at the dose of 1 mg/kg, tapered every 2 days and stopped at 10 days, in the SSG. The pure tone averages (PTA), speech discrimination scores (SDS) and the percentage of the patients who made an improvement more than 10 dB were analyzed on the tenth day and 2 months after the treatment statistically. The improvement in PTA on tenth day and second month after treatment was 31.38 and 37.55 dB, in the ITSG and 19.35 and 20.68 dB in the SSG, respectively. The improvement in SDS in the same time period was 35.24 and 37.52% in the ITSG and 20.13 and 19.61% in the SSG, respectively. Also, 25 of the 29 patients (86.2%) in the ITSG and 16 of the 31 patients (51.6%) in the SSG made an improvement more than 10 dB on PTA in the second month control. Intratympanic steroids gave better hearing results than systemic steroids with no systemic side effects. Studies with more sample sizes will identify the best steroid for injection, application time, frequency and dose.