Complementary and alternative medicine (CAM) are becoming increasingly popular in many medical situations, particularly among patients with cancer. CAM encompasses a range of modalities including dietary and vitamin supplements, mind-body approaches, acupuncture, and herbal medicines. In contrast to standard chemotherapeutic and hormonal regimens used for the adjuvant treatment of early-stage breast cancer, controlled clinical trials have generated few data on the relationship between CAM and the outcomes of recurrence or survival, or even overall quality of life and safety. The objectives of CAM treatments are manifold: the reduction of toxicities of therapy, improvement in cancer-related symptoms, enhancement of the immune system, and even a direct anticancer effect. The primary basis of CAM rests on empirical evidence and case studies, as well as theoretic physiologic effects. In some cases, laboratory or clinical data lend support to these modalities. Some types of CAM are based on ancient Oriental forms of medicine founded on centuries of experience documented through oral and written text. Nevertheless, the paucity of evidence in the clinical setting limits firm conclusions about the effectiveness or safety of most CAM approaches in breast cancer. This review will summarize the basis for the application of certain CAM modalities in the therapy of early-stage breast cancer and will highlight some of the directions of investigative work that could lead to a rational integration of CAM into conventional adjuvant therapy.