<p>Head and neck cancer patients receiving definitive treatment in terms of radiotherapy, chemotherapy or undergoing surgical treatment are prone to develop some form of acute and/or late complications. Esophagus is in close proximity with the treatment field of head and neck cancer and thus can predispose esophageal mucosa to chronic injury over the period of time. A prospective observational study was conducted on 50 patients diagnosed with head and neck cancer. The patients were evaluated by Eating Assessment Tool (EAT-10) questionnaire and Upper gastrointestinal (UGI) endoscopy. All patients were subjected to UGI endoscopy both pretreatment and 3 months following the treatment. Out of 50 patients, 50(100%) patients underwent upper GI endoscopy prior to starting the treatment for head and neck cancer. Normal endoscopic study was seen in 46(92%) patients. 2(4%) patients had synchronous esophageal cancer, 1 patient had esophageal varices and 1 patient had hamartomatous polyp. 3 months after the completion of treatment, 44(100%) patients who came for follow-up underwent upper GI endoscopy. Among these, 29(65.90%) patients had a normal esophagus, 12(27.28%) patients had developed esophagitis, 2(4.54%) patients developed esophageal candidiasis and 1 patient had stricture. Esophageal pathology can occur as a sequela of radiotherapy, combined chemoradiation with or without surgery. Hence, upper GI endoscopy should be included in the routine evaluation of patients with head and neck cancers to diagnose esophageal lesions early which will help in improved overall survival.</p>