Oncoplastic surgery combines plastic surgical techniques with sound surgical oncologic principles. The goal is to completely excise the cancer, with wide surgical margins while maintaining or improving cosmesis. For large, poorly defined, or unfavorably situated tumors, standard lumpectomies may lead to unacceptable cosmetic results in addition to close or involved resection margins. Similar problems may occur for smaller tumors in small breasts. Integration of the two surgical disciplines avoids or minimizes poor cosmetic results after wide excision. It increases the number of women who can be treated with breast-conserving surgery by allowing larger breast excisions with more acceptable cosmetic results. Oncoplastic surgery requires a multidisciplinary approach and thorough preoperative planning. It is absolutely necessary to enlist the cooperation and coordination of surgical oncology, plastic surgery, radiology, pathology, medical oncology, and radiation oncology. Oncoplastic surgery requires a philosophy that the appearance of the breast after tumor excision is important. J. Surg. Oncol. 2014 110:82–89. © 2014 Wiley Periodicals, Inc.