In a single generation the treatment of most women with early-stage breast cancer has changed dramatically. Clinical trials with more than 20 years of follow-up have documented that for appropriately selected patients breast conserving surgery, followed by whole breast irradiation, has an outcome equivalent to mastectomy. The appropriate selection of patients remains controversial. Questions remain regarding the role of new diagnostic imaging modalities, radiation therapy techniques, achieving optimal cosmesis, the choice and the timing of adjuvant chemotherapy, etc. To address these issues, the fifth international consensus conference of the Breast Health Institute, cosponsored by the European Institute of Oncology, was convened in Milan, April 29 through May 1, 2005. This article is a summary of the proceedings.