Radiotherapy is a reliable and effective treatment method for the treatment of head and neck cancers. This study was conducted as a descriptive work with the purpose of determining the symptoms experienced by patients with head and neck cancer who are undergoing radiotherapy. The study was carried out on 47 patients receiving treatment in oncology clinics. Data were obtained at mid-radiotherapy (RT), at the end of radiotherapy and 1 month after the end of radiotherapy using the Memorial Symptom Assessment Scale (MSAS) and Personal Information Forms. The mean scores of MSAS GDI (Global Distress Index), MSAS Physical, MSAS Psychological and Total Memorial Symptom Assessment Scale, which were highest by the end of radiotherapy, declined during the 1-month period following the end of radiotherapy. A statistically significant difference (p < .05) was found between the subscale groups in the evaluations made at mid-RT, at the end of RT and 1 month after the end of RT. Patients generally experienced symptom frequency, severity and distress levels at highest rates at the end of RT. During the radiotherapy process, determining these symptoms will contribute to improve the well-being of the patient. These results may be useful to control symptoms effectively.