Bilingualism is to be seen as dynamic bilingualisms-in-practice, which are continually being “performed,” that is, shaped, valued, and constituted, both through discourses which (re)contextualize the notion, as well as through the everyday language practices of bilinguals. To shed light on bilingualisms-in-practice, primarily in the context of one bilingual school in Wales, a range of data is examined to identify prevalent discourses on bilingualism. It is argued here that the meso level of society, especially educational institutions, constitute a key site for the recontextualization of these discourses and thereby play an important mediating role between the micro and macro levels of society.