Introduction: Breast cancer is the most frequent malignant neoplasm in women. This illness often makes women withdraw from their family life and work. They do not believe in a return to health and they cannot accept the fact of being ill. This is why social support is crucial to aid the patient in their struggle with the disease. Aim: The aim of this paper was to show a connection between the level and degree of social support and preferable health behaviors as an indicator of maintaining the optimal health condition. Material and methods: The study was carried out among 105 women with breast cancer treated on the Department of Radiotherapy and Department of Breast Diseases and Reconstructive Surgery of the Oncology Center in Bydgoszcz, Poland. Health behaviors were assessed with the use of the questionnaire of Health Behavior Inventory by Juczyński, and the level of support was evaluated with the Scale of Social Support by Kmiecik-Baran. Results: The examined women show a high level of health behaviors. Proper nutrition obtained the lowest score. The main source of support was their family and friends. The therapeutic team provided mainly information support. Of four types of support, the emotional type was assessed as the most effective, and the tangible one as the least effective. Conclusions: The results of the study may contribute to the deeper understanding of problems and needs of women suffering from breast cancer and enhance their motivation to combat the disease. The results may also influence patients’ health behaviors, which might cause faster convalescence or even help avoid the disease.