Unacceptable forms of exploitation of children at work exist and persist, but they are particularly difficult to research due to their hidden, sometimes illegal or even criminal nature. Slavery, debt bondage, trafficking, sexual exploitation, the use of children in the drug trade and in armed conflict, as well as hazardous work are all defined as Worst Forms of Child Labour. Promoting the Convention (No. 182) concerning the Prohibition and immediate action for the Elimination of the Worst Forms of Child Labour, 1999, is a high priority for the International Labour Organization (ILO). Recommendation (No. 190, Paragraph 5) accompanying the Convention states that “detailed information and statistical data on the nature and extent of child labour should be compiled and kept up to date to serve as a basis for determining priorities for national action for the abolition of child labour, in particular for the prohibition and elimination of its worst forms, as a matter of urgency.”\nAlthough there is a body of knowledge, data, and documentation on child labour, there are also still considerable gaps in understanding the variety of forms and conditions in which children work. This is especially true of the worst forms of child labour, which by their very nature are often hidden from public view and scrutiny.\nAgainst this background the ILO, through IPEC/SIMPOC (International Programme on the Elimination of Child Labour/Statistical Information and Monitoring Programme on Child Labour) has carried out 38 rapid assessments of the worst forms of child labour in 19 countries and one border area, and produced two reports on child domestic workers based on national statistics. The programme was funded by the United States Department of Labor. The purpose of the national reports is to provide an in-depth analysis of child domestic workers - a widespread worst form of child labour - at the country level. The report of South Africa made\nuse of the comprehensive statistics on working children collected through the national survey on child labour undertaken by Statistics South Africa (Stats SA) with the technical and financial assistance of IPEC/SIMPOC. The report of Brazil made use of data gathered by the National Institute of Geography and Statistics (IBGE) in selected years of the last decade. These countries were selected, taking into consideration the available national secondary data, and the need to shed more light on this worst form of child labour.