The objective of this study was to determine the effectiveness, dosage, safety and comfort of intratympanic steroids as primary initial treatment of idiopathic sudden sensorineural hearing loss (ISSHL). Prospective nonrandomized clinical practice study was performed in Tertiary referral center university hospital. A total of 35 consecutive patients suffering from newly diagnosed sudden sensorineural hearing loss with mean pure-tone average thresholds of 81 ± 21 dB were treated. No previous therapy had been undertaken. Intratympanic steroid injection as primary initial treatment was administered during 2 weeks on a twice a week schedule, between 2010 and 2011. Treatment was started on average within 2 days of symptoms onset. Pre and post-treatment audiometric evaluations were analyzed on follow-up as well as tolerance of the procedure and possible adverse effects. 66-85 % of patients achieved successful treatment according to the different outcome criteria used to evaluate hearing improvement (Furuhashi criteria/improvement of ≥10 dB in pure-tone average). Mean post-treatment improvement regarding pure-tone average was 34 ± 21 dB. A 48 ± 43 % improvement in speech discrimination score was observed. Patients received an average of 18 mg of methylprednisolone per injection and a total dose of 72 mg per treatment cycle. No serious adverse effects were noted. Intratympanic steroid injection is an effective, safe and well-tolerated office based-procedure for the treatment of ISSHL as primary initial treatment that can avoid the potential adverse effects of systemic steroids. A higher dose, schedule of administration as well as standardization of hearing recovery criteria still need to be established.