Public authorities in Europe are faced with increasing demands to accommodate religious diversity. This article traces some key issues concerning the limits of the secular State in Europe to accept and accommodate those ethno-religious minorities that are perceived to be partially different entities and claim some jurisdiction, without thereby rejecting guarantees from the receiving legal system. This multicultural challenge that minorities pose to institutionalized secularism is amongst the most complex political and long-term issues European states have to face. Such a challenge has not only to do with socio-economic disadvantage and discrimination in the labour markets but also with the constitutional status or corporate relationship with the State. On the other hand, European anxieties question whether or not Muslims can be and are willing to be integrated into European society and its political values; in particular, values of freedom, tolerance, democracy, sexual equality and secularism. Across Europe, multiculturalism seems to be in retreat and ‘integration’ is once again the watchword.