radiotherapy on the peripheral and central vestibular system. Consequently, the current Background: The ototoxicity of both chemotherapy and radiotherapy has been studied.Little is known regarding their impact on the vestibular system, particularly, the laboratory vestibular testing that evaluates the effects of both chemotherapy and research was designed to study Videonystagmography(VNG) and video head impulse test(vHIT) in patients with head and neck cancer receiving chemotherapy and radiotherapy for early diagnosis of vestibularsystem abnormalities. Methods: This study included two groups with head and neck cancer: group I included 19 patients receiving chemotherapy and group II included 19 patients receiving radiotherapy.Basic audiological evaluation,VNG, and vHIT were conducted on all patients before treatment and 3 months following treatment. Results: Regarding pure tone audiometry, there was a statistically significant increase in hearing threshold at high frequencies in patients receiving chemotherapy and radiotherapy before and after treatment.As regards the VNG test, there was a statistically significant impairment in saccade, smooth pursuit, optokinetic, and caloric tests in patients before and after receiving chemotherapy. However, in patients receiving radiotherapy, there was no statistically significant difference in the VNG test battery except for increased value of caloric weakness. vHIT abnormalities were reported in patients of both groups. Conclusions: This study demonstrated the ototoxic and vestibulotoxic effects of both chemotherapy and radiotherapy in patients with head and neck cancer.