This article is concerned with the way the French education system deals with new challenges in terms of language, while referring to the (traditional) general framework of language planning in the country. The same principles and mindset that governed the way regional minority languages were treated in the past are now largely determining the way the languages of immigrants and their speakers are treated and considered. We thus seek to remind readers how the theoretical and practical background to language planning in education functions in France, showing how historical factors led to considering linguistic diversity as an unnecessary heritage rather than as an asset. We then move on to examine the state of language teaching generally speaking in the education system, in order to provide a general outlook on the subject. Finally, we show that albeit seemingly monolithic at first, the French system can also accommodate diversity to a certain extent, through looking at two particular contexts.