Adenocarcinoma of the breast is the most common cancer of American women. Increased incidence and reduced mortality have generated a population of more than 2 million breast cancer survivors who require medical follow-up. In addition to therapy-related complications, these women are at risk for locoregional recurrence, distant relapse, and the development of second primary breast tumors. Medical surveillance after primary breast cancer treatment has historically included regular patient history and physical examinations, complete blood cell counts, comprehensive blood chemistries, tumor markers, mammography, chest x-rays, and sometimes computed tomography (CT) and nuclear medicine bone scans. The use of such intensive surveillance was based on the presumption that detecting disease recurrence at its earliest stage would offer the chance of cure, improved survival, or at least improved quality of life. Here we review the evidence that such intensive surveillance is not cost-effective, and in fact has no significant impact on the overall survival or quality of life of women diagnosed with early-stage breast cancer. Finally, we present an evidence-based approach to breast cancer surveillance after therapy that is consistent with several clinical practice guidelines, maximizing outcome and minimizing cost.