Sudden deafness is a disease of acute onset and on otologic emergency needed prompt treatment. But its pathophysiology is not fully determined, so treatment is controversial until now. In this study, we evaluated the therapeutic effect of Lasix-Vitamin and carbogen inhalation therapy on sudden deafness. We studied fifty six cases of sudden deafness, which were treated with bed rest, plasma expander, Lasix-Vitamin and carbogen inhalation therapy from May 1990 to April 1993. The effects were analyzed according to variables affecting the evaluation. And the results were as follows : 1) The therapeutic results were 13 cases(23.2%) of complete recovery, 15 cases(26.8) of partial recovery, 12 cases(21.4%) of slight recovery and 16 cases(28.6%) of no improvement. 2) Patients in age group below 40(80.8%) showed better recovery rate than that in over 41(63.3%). 3) Patients who were treated within 7 day from onset showed excellent recovery(86.0%), but the recovery rate decreased according to delay. 4) Patients treated with bed rest and admission(76.1%) showed better recovery rate than that without admission(50.0%). 5) There was definite different recovery rate between of this study(71.4%) and of nature(50.0%).