Mandatory reporting of child abuse and neglect is the law in a large number of nations, but not in the majority of all nations worldwide. Nations with the most experience of mandatory reporting of child abuse and neglect have the capacity to describe relatively detailed trends in its epidemiology and progress in various kinds of responses and prevention efforts. At the same time, countries that do not require reporting tend to have less information on the extent of child maltreatment within their borders, and less information on how well child abuse and neglect are addressed, treated and prevented through a variety of social and legal responses. Mandatory reporting laws have existed across the USA since the 1960s and are a well-known phenomenon in that country, although even there they remain contested theoretically, and continue to present multiple legal, clinical and practical questions. Even more signifi cantly for the purpose of this book, which has been designed for an international audience, issues surrounding mandatory reporting laws continue to be highly relevant worldwide. Countries continue to enact the laws, in jurisdictions as diverse as Saudi Arabia and India, and with legislation forthcoming in Ireland in 2015. Other nations such as the United Kingdom are currently in heated debates about whether the laws are a good strategy, with law reform efforts underway. Other jurisdictions continue to amend and refi ne their longstanding mandatory reporting laws, including many US states, and states and territories in Australia. Nations that have not adopted mandatory reporting laws often cite criticisms of them as a justifi - cation for not doing so, but those jurisdictions that have adopted the laws as part of their strategy to identify and respond to serious child maltreatment have concluded that the advantages outweigh any anticipated costs. Debates will no doubt continue in many jurisdictions around the world about the benefi ts and disadvantages of enacting the laws, the various forms in which they may be judiciously employed, and if adopted how to optimize their benefi ts while minimizing any disadvantages