This study evaluated the effectiveness of vitamins A, C, and E, with selenium, in the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL). This was a prospective, controlled study performed at a tertiary teaching and research hospital. Over a 32-month period, patients were treated with either our standard ISSNHL treatment regimen plus vitamins A, C, and E and selenium (ACE+ group) or with only our standard ISSNHL treatment regimen (ACE- group). The demographics, additional symptoms, mean initial and final hearing levels, mean hearing gain, and recovery data were compared between the two groups. The ACE+ group, consisting of 70 (55.5 %) patients, received vitamin A (natural beta-carotene, 26,000 IU), vitamin C (ascorbic acid, 200 mg), vitamin E (d-alpha-tocopherol, 200 IU), and selenium (50 μg) twice daily for 30 days in addition to our ISSNHL treatment regimen: methylprednisolone at an initial dose of 1 mg/kg body weight per day, tapered over 14 days; Rheomacrodex(®) [(10 g of dextran and 0.9 g of NaCl)/100 ml] 500 ml daily for 5 days; Vastarel(®) 20-mg tablet (20 mg of trimetazidine dihydrochloride) three times daily for 30 days; and ten 60-min hyperbaric oxygen (HBO) sessions (2.5 absolute atmospheres of 100 % O2), once daily, starting the day of hospitalization. The ACE- group comprised 56 (44.4 %) patients, who received only our ISSNHL treatment regimen. The mean hearing gains were 36.2 ± 20.3 dB in the ACE+ group and 27.1 ± 20.6 dB in the ACE- group. The mean hearing gain rates were significantly higher in the ACE+ group than in the ACE- group (p = 0.014). Treatment with vitamins A, C, and E and selenium was effective in ISSNHL patients undergoing treatment with methylprednisolone, dextran, trimetazidine dihydrochloride, and HBO, and might be more effective when the initial hearing level is below 46 dB.