Hygienic Re-Education: Health Colonies and the Medicolization of Child Welfare In the Netherlands between c. 1880 and 1970, large numbers of working-class children were subjected to a penetrating kind of hygienic re-education in 'health colonies'. The aim of the philanthropic societies that set up these colonies was twofold: to promote child health and to teach personal hygiene and proper behaviour. Compared to other Western countries, this Dutch version of the international hygienic campaign focusing on physically weak schoolchildren was characterized by groups staying in the health colonies for a short time, the absence of schooling and the major role played by physicians. Questioning the background of these particularities, this article discusses the rise, development and decline of the health colonies. Through subsidies and control, the Dutch State turns out to have played a major role in the process of medicalization of this originally pedagogical project.