ObjectiveBreast cancer is one of the most common cancers in women, particularly among older women. This illness along with its treatment has a great impact on a woman’s subjective opinion of her quality of life and functioning in everyday life. The aim of this research was to assess the quality of life in women undergoing radiotherapy for the treatment of breast cancer.Patients and methodsThe research was carried out in 120 patients with breast cancer undergoing radiotherapy in the Oncological Center in Bydgoszcz, Poland. Among the 120 examined patients, there were 30 women aged between 20–50 years and the remaining were over 50 years of age, including 42 women over the age of 60. Demographic and clinical data were collected and the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire (version 4) was used to assess health-related quality of life (HRQOL) of the patients. Statistical analyses were conducted using Statistica, version 10.0.ResultsPatients with breast cancer undergoing radiotherapy rated their quality of life with an average of 113.83 points. Older patients above 71 years of age also displayed significantly higher HRQOL (122.70 points). A lower level of fatigue was noticed among patients ≤50 years and ≥71 years of age. Education and marital status also had an important impact on HRQOL. Educated women with a good financial situation had a significantly higher HRQOL, compared to those with a lower education and in poor living conditions.ConclusionHRQOL and state of fatigue in breast cancer patients treated with radiotherapy depended upon their age. Both were high among women aged 71 years and above, while younger patients (51–70 years of age) had slightly lower values. Results suggest that sociodemographic factors influence the conditions of life of women treated with radiotherapy for breast cancer in a significant way. Overall, patients tolerated this type of treatment well.