Complementary and alternative medicine (CAM) has gained popularity among cancer patients in the past years. For this study, CAM includes any group of health care systems, practices or products that are not considered to be part of conventional medicine at present (National Center for Complementary and Alternative Medicine). The present study assessed patterns of CAM use in breast cancer patients in Europe. The study used a descriptive cross-sectional design, and data were collected through a 27-item questionnaire. The sample, which was part of a larger study, consisted of 282 breast cancer patients from 11 countries in Europe. Among participants, 44.7% used CAM since their diagnosis of cancer. The most common therapies used included herbal medicine (46.4%) and medicinal teas, relaxation techniques, spiritual therapies, homeopathy and vitamins/minerals. Younger patients with higher education and who had received combination treatments for their cancer in the past were more likely to use CAM. High levels of satisfaction were reported, with only 6.5% of the women reporting no benefits from the CAM used. Main sources of information about CAM were mostly friends/family and the media. Findings suggested that a high proportion of breast cancer patients used CAM, which may have implications for the clinical management of these patients.