Faced with three cases of bilateral simultaneous breast cancer over a short period of time, we asked ourselves whether we were dealing with a specific anatomo-clinical entity, what is the prognosis, and what should be the best therapeutic approach. The medical literature is characterized by a small number of papers devoted specifically to this topic and no possible comparison among these papers, because of their differences in the definition of bilateral simultaneous breast cancer. However, our review of the literature led us to think that bilateral simultaneous breast cancer is not a specific entity, and also that the presence of a contralateral simultaneous breast cancer does not worsen the prognosis. Therefore, the treatment should not be different from the treatment of a unilateral breast cancer.