Although many studies are available concerning the treatment of sudden deafness using hyperbaric oxygenation, only a few of these deal with tinnitus. The aim of the present study was to evaluate the therapeutic use of hyperbaric oxygenation in cases of tinnitus. A total of 193 patients, having undergone primary intravenous hemorheologic therapy, were treated with hyperbaric oxygenation. Tinnitus was evaluated before, after ten sessions and after 15 sessions using a tinnitus questionnaire. Additionally, an audiometric examination was performed. Measurable improvements of the tinnitus occurred in 22% of the patients, whereas a moderate improvement was seen in 17% of cases. 10.4% showed an excellent improvement and tinnitus disappeared completely in two patients. The improvement rate decreased in those cases where the time from onset of tinnitus exceeded 40 days. In conclusion, hyperbaric oxygenation seems to be a moderately effective additional treatment in the therapy of tinnitus after primary hemorheologic therapy, provided the time from onset of tinnitus is less than 1 month.