Objective: This in-depth review of the multidisciplinary approach to early breast cancer treatment (in situ, stage I and II) will update the surgeon about the indications, risks, and benefits of breast surgery, radiation therapy, adjuvant chemotherapy and hormonal therapy, and the importance of breast reconstructive surgery. Summary Background Data: Breast cancer will occur in one of eight women in the United States during their lifetime and is the second leading cause of death in women from cancer. The practice of multidisciplinary breast cancer treatment has become the standard of care for the majority of breast cancer patients. If the surgeon is to retain the primary coordinating role in breast cancer management, then he or she must fully understand all modalities of oncology therapy and know how to deploy them to benefit individual patients. Conclusions: This article provides a framework for making clinical decisions about the appropriate combination and sequence of treatment for various presentations of early breast cancer.