"Brazil is the world champion of caesareans." This prowess points out a serious public health problem. While the increase in the percentage of caesareans among all deliveries is an international phenomenon, it is highest by far in Brazil, where caesareans account for nearly 40% of births, that is, three times the maximum recommended by WHO. This abusive practice appears pandemic and has spread in recent years throughout the entire country, although at divergent rates. It weighs heavily on Brazil's national health insurance fund. After a critical examination of the information sources related to births, we analyze successively the principal factors likely to explain this abuse: level of development, emergence of family planning and the association of caesarean delivery with tubal ligation for sterilization purposes, and tension within the healthcare system, especially the role of private physicians in urban areas. By studying these aspects of the problem in their geographic dimensions, we find important regional differences that must be considered in defining policies to limit this excess.