Small breast cancer is not a clear entity and is often very difficult to classify (e.g. TNM). The role of radiotherapy is far from being generally accepted; it is now clear that the smaller the tumor is, the better are its chances to be cured by X-rays. The first step after diagnosis is the search for distant metastases. That postoperative radiotherapy increases the risk of distant metastases remains to be proved and clinical trials are under way. At the present time, the treatment of breast cancer requires a multidisciplinary approach.