In the past few years the treatment of early stage breast cancer has gone through several important changes. Both chemotherapy and hormonal therapy have been shown by large, randomized trials to offer a survival advantage. The most commonly used chemotherapeutic agents used in the US are doxorubicin and cyclophosphamide (AC). However, 3 studies have suggested that there may be an advantage in the use of taxanes in the adjuvant treatment of breast cancer. Furthermore the use of dose dense chemotherapy, incorporating AC and paclitaxel, has shown very promising results. It is well established that tamoxifen (T), a selective estrogen receptor modulator (SERM), improves overall survival (OS) in women with hormone receptor (HR) positive breast cancer. However, the results from large multicenter, randomized trials, suggest the potential superiority of aromatase inhibitors (AIs), compared to T or an advantage of sequencing T followed by an AI. The role ovarian suppression is still being investigated in patients who have received prior chemotherapy. Newer agents, such as the monoclonal antibody against the her2/neu receptor, trastuzumab, are now being studied as adjuvant therapy in early stage breast cancer. In the next few years, with the completion of several large randomized trials, we will be able to answer several questions, including the optimal way of incorporating AIs into the adjuvant therapy, the long-term sequella of using trastuzumab in the adjuvant treatment of breast cancer and the role of ovarian suppression combined with an AI in premenopausal women with breast cancer.