The publication of the new Cochrane review on screening for breast cancer with mamography has revived the debate on breats screening and raised some new topics. Whereas the Cochrane reviewers reasserted on their previous conclusion of the lack of efficacy of breast screening, the new review of the Swedish studies, the new systematic review of the Agency for Healthcare Research and Quality commissioned by the US Preventive Services Task Force, and the recent review of an IARC working group supported the efficacy of breast screening after carefully considering the methodological quality of trials. Nevertheless, the efficacy of breast screening for younger women remains controversial. The present controversy has raised other issues like the measure of the benefit in screening trials or the potential adverse effects of screening, particularly, overdiagnosis and its impact on therapy that are discussed in this papers. It also stresses of evaluating screening before introducing it and the need to inform the population about the benefits and the potential harms and about uncertainties about cancer screening.