Introduction: Diabetes Mellitus is a worldwide chronic systemic disorder that is characterized by deficiency in insulin secretion from pancreas and/or impairment in its action in its target tissues, which affects daily activities and shortens lifetime, requiring a lifelong management program, resulting in glucose impairments in inner ear leading to vestibular and/or auditory dysfunctions. Aim: The aim of this study was to assess the impact of type 1 DM and type 2 DM on vestibular system using vHIT and cVEMP. Methods: This study included 45 patients divided into 3 groups: 15 type 1 DM (Group 1), 15 type 2 DM (Group 2) and 15 apparently healthy age controls (Group 3). All patients were subjected to: Full history taking, Otoscopic and basic audiological examination, Vestibular evaluation including: arabic questionnaire version of "Dizziness Handicap Inventory" (DHI), cervical vestibular evoked myogenic potentials and video head impulse test. Results: Results of this study revealed that there were statistical difference in P13, N23 latencies of cVEMPs, lateral canal gain of vHIT and in lateral canals gain asymmetry. Olso, there were no statistical differences in peak to peak amplitude or asymmetry ratio and in posterior and anterior canals gain, also no significant differences in RALP and LARP gain asymmetry between control and diabetic groups. Conclusions: Diabetes affects vestibular system at different levels. Type 1 has more prominent effect than type 2. cVEMPs and vHIT has different pathways. Accordingly, they are used as complementary tests in diagnosis of vestibular affection in diabetes. Key words: DM, cVEMP, vHIT.