Abstract Objectives Some patients with sudden sensorineural hearing loss (SSNHL) are frustrated by residual tinnitus even after accomplishment of the treatment for SSNHL. In the present prospective study, we examined patients’ backgrounds of sex, laterality and age together with changes in hearing level and the tinnitus score after the onset of SSHNL to determine the prognostic factors of residual tinnitus after the final day of medical treatment for SSNHL. Methods Forty-four patients with SSNHL were all treated with systemic administration of steroids for 2 weeks and oral intake of vasoactive drugs and vitamin B12 for 6 months before accomplishment of the treatment for SSNHL. The hearing improvement rate (HIR) was determined by comparing the hearing level before and 6 months after the start of treatment. Tinnitus was subjectively evaluated by the tinnitus scoring questionnaire before, 6 and 24 months after the start of treatment. The score of a five-step evaluation of subjective tinnitus feelings, “loudness”, “duration” and “annoyance”, was recorded. Results HIR was significantly correlated with tinnitus score improvement (TSI) in “duration” at 6 months after the start of treatment compared with before treatment. The tinnitus score of all 3 items was significantly improved 6 months after the start of treatment compared with that before treatment but it was not significantly changed between 6 and 24 months after the start of treatment. TSI in “duration” between 6 and 24 months was significantly correlated with the patients’ age and HIR using multiple regression analysis. Conclusion According to the tinnitus scoring questionnaire, “duration” is the most reliable item for subjective evaluation of tinnitus accompanied by SSNHL. Generally, subjective feelings for residual tinnitus 6 months after the start of treatment for SSNHL are supposed to be almost the same, even at the 24th post-treatment month. Especially, younger patients with better hearing improvement are predicted to achieve further improvement of tinnitus between 6 and 24 months after the start of treatment.