Purpose: To understand the real efficacy of transtympanic steroid therapy for sudden sensorineural hearing loss (SSHL) in patients in whom traditional therapies have failed. Procedures: A prospective study was designed in order to evaluate hearing improvement in SSHL patients treated with transtympanic therapy. A solution of methyl-prednisolone (MP) and sodium bicarbonate was administered via a transtympanic injection to 8 patients. Hearing level was evaluated before therapy and at days 1, 7 and 30. Results: Hearing improvement was obtained in 75% of the patients. The patients in this category are usually considered untreatable. Conclusion: Transtympanic steroid therapy is an efficacious solution for patients affected by SSHL in whom traditional therapies have failed. Further studies will be required to identify the most favourable dosage, route of administration and type of steroid. Transtympanic steroid application is safe, inexpensive, easy to perform and efficacious in cases of SSHL not responsive to traditional therapy.