Breast cancer is the most common cancer in women in Europe and Northern America. Its incidence and mortality rates are increasing with advance in age. Only few elderly women with breast cancer are treated in clinical trials. Elderly women with the same numerical age are very heterogeneous considering their biological age. Geriatric medicine has established comprehensive geriatric assessment (CGA) to get important information on elderly patients missed by a routine clinical history and physical examination. The data collected in CGA are of prognostic relevance for mortality, morbidity, maintenance of independence and utilisation of health care resources. Within the last few years, some research groups have demonstrated that the use of CGA in elderly cancer patients collects information missed by the currently established workup of these patients and that this information is of prognostic relevance concerning toxicity of chemotherapy and mortality. The use of CGA in a population of general elderly patients improves functional status and mental health, but so far no effect on mortality could be demonstrated. A subgroup analysis of the elderly cancer patients within this trial additionally demonstrated an improvement in pain control. Special data concerning the use of CGA within the group of elderly breast cancer patients are not published so far. The authors suggest areas of care for elderly women with breast cancer within which the CGA might be able to improve treatment and which should be a field of randomised controlled trials in the future.