A little more than 100 years ago Halsted pioneered a surgical approach that led, for the first time, to the cure of breast cancer in some patients. Veronesi's contribution was to offer the same possibility while considerably reducing the mutilation that went with cure. This article reviews the development of the conservative surgical approach in breast cancer and synoptically presents the results of large-scale clinical trials conducted by Veronesi's group in Milan in the 1970s and 1980s to demonstrate the efficacy of quadrantectomy, radiotherapy and axillary dissection (QUART) as conservative treatment for small size breast cancer. These studies set in motion the world-wide trend to conservative surgery in all forms of cancer. The article goes on to describe the surgical procedures of quadrantectomy and complete axillary dissection as developed by Veronesi, and outlines new indications for, and developments of this established conservative technique.