ABSTRACT: Background: Interstitial lung diseases (ILD) are a group of diffuse parenchymal lung disorders associated with cough, dyspnea, hypoxemia and restrictive pulmonary function. Vertigo and dizziness are early symptoms of cerebral hypoxia Aim: The aim of this study was to assess the effect of hypoxia and chronic cough in patients with ILD on central and peripheral vestibular functions. Method: A cross sectional study was conducted in Audio-vestibular unit, ENT Department and Chest Department, Zagazig University Hospitals. Sixty two patients diagnosed to have ILD were included. Full VNG test battery was done. Results: There was statistical significance decrease in mean of optokinetic speed and smooth pursuit gain at high frequency (0.6) in both Rt & LT sides among cases who had moderate hypoxia compared to cases who had mild hypoxia). No difference was found between mild and moderate cases in other oculomotor tests parameters. Also, there was statistical significance increase in frequency of BPPV among cases who had moderate hypoxia compared to cases who had mild hypoxia. Conclusions: Degree of hypoxia was correlated with both central and peripheral vestibular functions. Keywords: ILD, vestibular function, hypoxia, VNG