PURPOSE: The purpose of this prospective, randomized, multicenter clinical trial was to compare the therapeutic efficacy of systemic versus intratympanic versus combined administration of steroids in the treatment of idiopathic sudden sensorineural hearing loss.METHODS: 102 patients with an up to 14 days history of idiopathic sudden sensorineural hearing loss were randomized to 1 of 3 arms and followed prospectively. Group A (35 patients) received prednisolone intravenously followed by methylprednisolone orally, whereas Group B (34 patients) were administered intratympanic methylprednisolone. Patients in Group C (33 patients) were administered the combination of the above-mentioned treatment modalities. The patients were followed-up with pure tone audiograms on days 1 (initiation of treatment), 3, 5, 10, 30 and 90.RESULTS: The final mean hearing gain was 29.0 dB HL for Group A, 27.0 dB HL for Group B and 29.8 dB HL for Group C. The differences between the three groups were not statistically significant. When hearing improvement was assessed according to Siegel's criteria, no statistically significant difference was recorded either. Furthermore, patients younger than 60 years old achieved significantly better hearing outcomes.CONCLUSIONS: The results demonstrated that systemic, intratympanic and combined steroid administration have similar results in the primary treatment of idiopathic sudden hearing loss. Younger patients are more likely to achieve better hearing outcomes.