The aim of this study was to assess hearing threshold levels in patients with diabetes mellitus, correlate degree of hearing loss with duration and severity of hyperglycaemia and complications of diabetes mellitus. Retrospective study was carried out from Jan 2018 to Dec 2018. Patients of previously diagnosed cases of type 1 and type 2 diabetes mellitus aged less than 60 years were subjected to fasting, post prandial blood glucose levels and pure tone audiometry were evaluated and compared with age matched controls. The results showed significant difference in hearing threshold with mild to moderate sensorineural hearing loss in both type 1 and type 2 diabetes mellitus patients. Diabetics with poorly controlled blood sugar level have increased risk of hearing loss.