This article deals with one of the aspects of a pluralistic society: the existence of informal marriages. These are marriages concluded in accordance with religious or cultural traditions that do not comply with the requirements of the formal secular legal order. Two aspects of those marriages will be discussed: primarily, whether and to what extent spouses in informal marriages should be regarded and protected by law as spouses, and secondly, whether spouses who are involuntary kept in their informal marriages should be released by and protected by formal law. With regard to both aspects the question will be raised whether human rights could and should serve as a means to offer spouses of informal marriages their desired protection. From recent case law both from the European Court of Human Rights and the national courts, it becomes clear that human rights have only recently and very cautiously started to demand a role in the informal legal orders.