peer reviewed ; Divergent bodies of theory have devoted ample attention to ethnic intermarriage. Using the data from the Belgian TIES project (The Integration of the European Second Generation), this paper focuses on the young Turkish and Moroccan second generation in Belgium and, in contrast to other studies in the field, includes cohabitation in addition to marriages. Furthermore, it distinguishes not only partnerships to natives versus partnerships to nonnatives but three types of partnerships: those to first generation partners, second generation partners and ‘native’ Belgian partners. Our results show, first, that a large part of the second generation lives with first generation coethnic partners. We find secondly that most of the relations to Belgian-born persons are in fact relations to partners of second generation from the same ethnic background. We conclude that estimations of intermarriage/cohabiting unions based on relations to first generation immigrants seriously underestimate the extent of intra-ethnic partnerships. Thirdly, we find that not only individual characteristics but also the social environment impacts on the partner choice.