In December 2003, the Stasi Commission, appointed by the President of France, recommended prohibiting public school students from wearing conspicuous religious symbols or apparel. This recommendation was quickly enacted, becoming the Law of 15 March 2004. This law is meant to be an application of the "principle of laïcité," which is part of the French Constitution. The law speaks in terms of a general prohibition, but in fact essentially targets the wearing of the headscarf by young Muslims, a practice that had been permitted in French schools since late 1989. The present article attempts to explain the particular conditions within which the problem arose in France and to render an account of the work of the Stasi Commission, of which the author was a member. In conclusion, the article offers a critical evaluation of the effects of the law.