In this paper, the authors offer an analysis of the relation between the intended and the implemented curriculum for primary education in Argentina, from the origins of the Argentine education system to the present day. They introduce the concept of "curricular regulation" as a method of analysis that includes not only the processes defining a given curricular policy and its contents, but also the processes through which this curricular policy is transmitted to the agents who have to put it into practice, and the processes through which this curriculum is enforced. Their point of view is that two models of curricular regulation can be identified in the history of the Argentine education system. The first model, which is analysed in the first part of this paper, was the initial centralized system that was designed when the Argentine education system was being consolidated and expanded--a period that started during the last decades of the 19th century and started to collapse around the 1970s. This model sought to guarantee the teaching of the same content to every student in order to homogenize their instruction in values, language, and the other knowledge necessary for participation in civic life. The basic idea was to give "equal" opportunities to students by offering "equal" educational contents. The second model of curricular regulation appeared in Argentina with the global educational reform that was implemented following the "Ley Federal de Educacion," adopted in 1993. This model was based on the idea that if an education allowing for social inclusion is sought, the principle of equality of opportunity through homogeneous education offered to all should be displaced by the principle of "equity" ("equidad"), meaning that children should be offered "equivalent opportunities" that respect their different cultural backgrounds. The second part of this paper examines how this model was implemented in an effort to change the way in which contents were selected for theArgentine education system.