Old age is strongly associated with comorbidity and decreased functioning, which in turn affects treatment decisions for elderly breast cancer patients. In recent years, the rate of elderly patients with breast cancer who were not operated on has increased considerably. Older age and an increased number of concomitant diseases are associated with an increased risk of postoperative complications. Mortality is higher in patients who experience complications than in patients who do not. The death of a patient who experiences a complication does not result from the complication itself; rather, it is associated with factors that make such a patient vulnerable e.g. comorbidity and poor functional status. Hormonal therapy could be a good alternative for surgical treatment in vulnerable elderly patients, but sound research into this is lacking. Deciding against the surgical treatment of elderly patients with breast cancer based on the fear of postoperative mortality is not justifiable; however, there is too little evidence on the consequences of breast cancer surgery on outcome measures such as quality of life and functional status yet available to be able to offer strong recommendations on the surgical treatment of elderly patients with breast cancer.