Background: In this study, our aim was to investigate the effect of factors, such as radiotherapy, the dose of radiotherapy, the region of radiotherapy, the age of the patient, performance, co-morbidity, the stage of the disease and the therapy modalities on the quality of life of patients with head and neck cancer. Materials and Methods: Eighty-two patients who were treated by either chemoradiotherapy or radiotherapy, at the Cumhuriyet University Faculty of Medicine, Department of Radiation Oncology, between February 2007 and September 2010, for head and neck cancer were included. The quality of life European Organisation for Research and Treatment of Cancer, Questionnaire module to be used in Quality of Life assessments in Head and Neck Cancer (EORTC QLQ-H&N35) questionnaire was conducted in all patients before starting the radiotherapy, in the middle, at the end, at 1 month and at 6 months after the treatment. Results: According to the questionnaires at the end and at the $6^{th}$ month after the radiotherapy, it was found that the age of the patient, co-morbidity, ECOG performance state, localization, type of treatment, the stage of the disease, the dose and the region of radiotherapy affect some of the symptom scales for quality of life. Conclusions: Quality of life was affected negatively during and after the radiotherapy. However, in the $6^{th}$ month after the therapy, a significant improvement was observed in most symptoms.