Brazil Water Series is the result of a joint work by the World Bank and its national partners since 2003. It raises issues and discusses solutions to the main problems on the water resources agenda in Brazil. This publication presents a relevant theme: the safety of dams. The benefits from dams include electric power supply, water storage for crops and drinking water. However, dams get old and the number of new dams increases each day requiring actions at all stages: design, construction, operation and decommissioning. Any defect of the structures may cause serious malfunction or even a rupture, causing economic, environmental losses and loss of human lives. Although the theme has been under discussion for decades, only in September 2010 the law no. 12,334 was promulgated ruling about it. Greater interest and attention has been raised since then thanks to the efforts of the National Water Agency (ANA) - central institution for dam safety management. This volume closes three years of technical assistance from the World Bank to ANA on dam safety. We hope that the lessons help shape future investments, build knowledge, facilitate intersectoral integration and strengthen institutions involved in the topic.