Objectives/HypothesisThe aim of this study was to compare the hearing results of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) who initially were treated with either a combination therapy of systemic steroids (SS) and intratympanic steroid injection (IT-S) or SS only. MethodsThe study followed a retrospective case-control design. One-hundred five patients who were diagnosed with ISSNHL and required treatment via admission were enrolled in this study. The control group (n = 53) was treated with SS, and the study group (n = 52) received SS as well as IT-S. We divided the patients according to pretreatment hearing levels. The outcome measured was improvement after the treatment audiology data at pretreatment were compared with those at day 10 and > 90 days after the treatment. Outcome data were analyzed using the t test, Pearson's (2) test, Fisher's exact test, and multivariate analyses of covariance with adjustment for pretreatment hearing levels. ResultsAfter more than 90 days, the average pure tone audiometry (PTA) in the control and study groups were 54.8 31.4 dB and 43 31.2 dB, respectively (P = 0.013). Hearing recovery rate was 57.7% in the control group and 69.8% in the study group. The hearing gain of the study group was higher than that of the control group at high frequencies within the 10 days of the treatment period. Analysis between subgroups, divided according to the severity of pretreatment hearing level, showed that the recovery rate was higher at all frequencies in the study group than in the control group in patients with mild to moderate hearing loss (pretreatment PTA < 70 dB). However, in patients with severe to profound hearing loss (pretreatment PTA 70 dB), the hearing outcomes of the study and control groups were not significantly different, except at a low frequency. ConclusionThe results of this study suggest that the treatment of ISSNHL with combination therapy results in higher hearing recovery rates when compared to treatment with SS alone, even in patients with severe hearing loss. Level of Evidence3b. Laryngoscope, 126:1871-1876, 2016