목적: This study aimed to identify the efficacy and appropriate target group of intratympanic steroid injection (ITS) in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). 방법:Fifty five ears treated with concomitant ITS and systemic steroids and 165 ears without ITS treatment were identified. Each case had 3 controls matched according to the age, sex and presence of vertigo. Patients were divided into subgroups according to pure tone audiometric configuration and the levels of initial hearing loss. Hearing results, frequency related hearing gain were investigated. 결과:Additional ITS was shown to be effective for patients with ascending type audiogram or patients with Grade-3 (60-90 dB) initial hearing loss. However, concomitant ITS resulted in negative effect on hearing in patients with Grade-1&2 (<60dB). ITS showed significant (p < 0.05) hearing improvement at 250 Hz in Grade-3 (60-90 dB) and Grade-4 (>90 dB) ITS subgroups. 결론:The efficacy of additional ITS for ISSNHL was different among subgroups with various levels of initial hearing loss or audiogram configuration.