Since 1955 Argentina's state agenda designated slums as a specific problem and have devised solutions that combined eradication and housing provision. In 1990 this interpretation changed: informal settlements, while emerging as a problem, also emerged as a solution that had to be accompanied by settlement and property regularization policies. The article aims to analyze the transformation of these problematizations from a critical history of thought. Using the genealogical method, it argues that the regularization proposal emerged when the existence of the settlements and the state's inability to solve the problem became naturalized.