Objective To investigate the effect of intratympanic dexamethasone injection for sudden hearing loss in patients with diabetes. Methods 46 diabetics with sudden hearing loss were assigned to treatment group (n=21) and control group (n=25). Simultaneously vasodilation, neurotrophy and insulin hypoglycemia were administered in both groups. Patients in treatment group were additionally managed with intratympanic dexamethasone (5 g/L) injection five times within 10 days. Pure tone test was conducted after intervention. Results The overall effective rates of the treatment group and the control group were 71.4% and 40.0% respectively, and the difference was statistically significant (P<0.05). No unexpected adverse events such as acute otitis media, perforated tympanic membrane and worsening in hearing occurred during the injection and follow up period in the treatment group. Conclusion Intratympanic dexamethasone injection is an effective treatment for sudden hearing loss in patients with diabetes and can avoid undesirable side effects. Therefore, intratympanic dexamethasone injection may be a reasonable alternative as an initial treatment of sudden hearing loss in patients with diabetes.