Innovative strategies for the treatment of breast cancer are being developed in four main directions: (1) the rapid move of new very active cytotoxic agents, such as the taxanes, to the first-line therapy of metastatic disease and to the adjuvant setting; (2) the careful reevaluation of high-dose chemotherapy in well-designed, prospective, randomized clinical trials, some of which already incorporate the taxanes in the treatment scheme; (3) the development of new therapies that are the result of our growing understanding of breast cancer biology, such as drugs directed at cell-signaling targets, antiangiogenesis and antimetastatic drugs, differentiating agents, telomerase inhibitors, and gene therapy; and (4) the investigation of new forms of immune therapy. These promising new therapies are reviewed and briefly discussed.