Sentinel lymph node biopsy has evolved as the surgical procedure of choice for women with clinically negative axillae, as part of an effort to move toward the less invasive surgical management of breast cancer. Axillary lymph node dissection remains the standard of care for patients with a positive axillary node and was previously performed on all patients with breast cancer prior to the implementation of the sentinel lymph node biopsy. There is, however, controversy regarding whether or not all patients with a positive sentinel lymph node need to undergo completion axillary dissection for either prognostic or therapeutic purposes. This article reviews the literature related to this controversial and evolving topic.