Abstract This article provides a critical analysis of the language policy measures that were taken by the Flemish government (Belgium) to improve the quality of the teaching of the national language (Dutch) in compulsory education in Flanders and in the Flemish education system in Brussels. It builds on Van den Branden (2006a) , which documented the implementation of task-based language teaching (TBLT) in primary, secondary and adult education in Flanders in the period between 1995 and 2005. Focusing on primary education, this article examines the different periods and trends in the government’s attempts to push the innovation of Dutch language education, and analyses its impact on the practice of teaching the language of schooling. The article highlights the gradual shift in focus from introducing TBLT materials and supporting the individual teacher to mandating the design of a school-wide language policy involving the whole school team, and from a top-down implementation to a more bottom-up driven, collaborative innovation process. The major aim of the article is to identify the factors that impacted on the effects of the innovation policy, against the backdrop of the growing influx of pupils who do not acquire Dutch (the main medium of instruction) as their mother tongue.