This book aims to investigate the presence of the hygienist discourse for School Groups in the educational legislation of Rio Grande do Norte, in the period 1908-1925. To this end, we start from the hypothesis that the influence of the hygienist discourse in the legislation expresses a project of modernisation in society that is linked through the School Groups. As for the theoretical-methodological framework, we adopted Michel Foucault’s theorisations as an instrument for the research work, in order to analyse the discourse present in the educational legislation in the north of Rio Grande do Sul, considering an understanding of the relationship between discourse and power based on the regulatory nature of the legislation; and also the concepts of normalisation and biopolitics. The main sources were: Laws, Decrees, Reports, Government Messages, Regulations, Regiments and Teaching Programmes. In this way, we found that the discursive practice examined in the legislation in northern Rio Grande do Sul was a means of understanding the socio-political, historical and educational moment permeated by power relations that sought to use the school groups as hygienist devices.