Summary In the context of Mexico in the 1940s (1942-1948), and based on the consultation of various Indian official documents, in particular the considerations on the indigenous problem, this article argues that cultural change was at the heart of the idea, programme and actions of the Inter-American Indigenous Institute. The foundation of the Institute (1942) and the context for drafting the Considerations (1948) are first studied. This was followed by the role that anthropology played in Mexican and inter-American indigenism. Finally, the processes of socio-cultural change (modernisation) proposed by the Institute as its main purpose are analysed. In the context of the relationship between the State and anthropology, one of the contributions of this text is to take into account the role of “modernisation” (such as induced and forced cultural changes) in the Institute’s programme and its Indian policies.