This article discusses the incorporation of ideas about hygiene and public health into urban projects in Santiago de Chile. Changes in the institutional framework were supported and led by professionals that worked closely with the State. The article covers the period from 1892, when the Hygiene Council (Consejo de Higiene) was founded, to 1927, when the Ministry of Welfare (Ministerio de Bienestar) was created to take charge of public health. By focusing on institutional components rather than theoretic discussions, this paper also intends to contribute to an understanding of urban modernization in Latin America during the twentieth century. While hygienic issues appeared from the late nineteenth century as an explicitly urban concern, precedents can be dated back to the late Colonial era when the Bourbons raised similar questions, with more or less effectiveness, in most Hispanic colonial territories. For this reason, the article includes a first section that deals with the notable efforts of that period to improve urban hygiene - efforts that are crucial to understanding the contemporary Latin American city.