Head and neck cancers may lead to malnutrition in patients because of the natural course of the disease and treatment-related complications. A 36-year-old patient who experienced pain and nutritional difficulties due to mucositis after combined chemoradiotherapy for nasopharyngeal cancer was found to be at risk for malnutrition. To prevent the development of malnutrition, it was decided to feed him through a percutaneous endoscopic gastrostomy (PEG) tube, and sufficient calorie intake was provided. The PEG tube was removed after alleviation of symptoms and achieving adequate nutritional performance that could meet all calorie needs with oral nutrition. It should be kept in mind that early recognition of the malnutrition risk in patients with malignancy and a proactive approach to nutrition will contribute to the regression of existing complaints in a short time and the patients’ regaining their former performance.