Much research on multilingualism in advertising has been undertaken in comparatively mono-lingual settings. Whereas such research may provide insights into the connotations of lan-guages used in advertising, research in more multilingual contexts can also provide different kinds of insights regarding the relative status of languages in a multilingual environment. This article focuses on multilingualism in written advertising in the highly multilingual setting of Luxembourg, where the language situation is currently undergoing significant change due to patterns of globalisation and migration. Analysis of a mixed corpus of advertisements, includ-ing 1,038 advertisements in the free daily newspaper l’Essentiel from 2009 to 2011, as well as selected further advertisements from elsewhere within Luxembourg’s linguistic landscape, reflects a move within Luxembourg in general from a longstanding trilingualism in French, German and Luxembourgish to different kinds of multilingualism, incorporating both the presence of new languages and changes in the relative roles of French, German and Luxem-bourgish. Particularly significant is the presence of Luxembourgish as a written language of advertising, whereas it traditionally functioned mainly as a spoken language in Luxembourg. The article presents the results of a quantitative and qualitative analysis of the advertisements and discusses how multilingualism in written advertising provides a pertinent window on changing forms of multilingualism in Luxembourg.