Breast cancer is acknowledged as an international priority in health care. It is currently the most common cancer in women worldwide, with demographic trends indicating a continuous increase in incidence. In the World, it is estimated that by 2020 there will be approximately 2,000,000 new cases of breast cancer per year. The enormous burden placed by this disease both on the population and on health care systems explains the increasing efforts and resources that have been devoted over the years to the search for a systematic and optimized strategy in breast cancer diagnosis and treatment. Today, the Breast Unit model is identified as the gold-standard to ensure optimized patient-centered and research-based clinical services for breast cancer patients improving survival rates and patients’ quality of life by a multidisciplinary approach in breast care. The present work reviews the lines of development of this multidisciplinary model of breast cancer treatment and analyzes the requirements of a high quality Breast Unit, its potential advantages and the many open issues that still require proper definition and implementation.