Adjuvant chemotherapy in breast cancer has clearly been shown to reduce mortality. The benefits extend to pre- and postmenopausal women and those with node-negative, node-positive, estrogen receptor (ER)-positive, and ER-negative disease. Updated data regarding chemoendocrine therapy in postmenopausal women and anthracycline-based regimens are presented. Dose intensity, dose density, and high-dose therapy have not been proven efficacious to date, but further trials are pending. The incorporation of taxanes and bisphosphonates has been further elucidated, with follow-up studies in progress. The potential role of trastuzumab is the focus of several clinical trials. Recent findings regarding the long-term side effects of adjuvant therapy are reviewed. These risks may outweigh the benefit derived from chemotherapy in a subset of patients who have excellent overall survival (OS) with small tumors, good prognostic features, or favorable histologic subtypes. This report will review the current state of adjuvant chemotherapy for early-stage breast cancer.