Between 1989 and 2003, nine European countries (Denmark, Finland, Iceland, Norway and Sweden, Germany, Belgium and France) gave same-sex couples the possibility of having their union registered by a state representative and of thereby acquiring legal rights and obligations. To determine the frequency of these alternative forms of union recognition, the classic measurement tools must be adapted to a new reality that gives prominence to categories that were habitually neglected. Legal recognition of same-sex couples is considerably less frequent than that of different-sex couples, despite the shift away from the institution of marriage. The new laws are probably judged too far short of the marriage laws to be attractive, and at the same time are too similar to them to match the specific needs of the couples they target. In addition, the frequency of registration varies between the different countries, and to a much greater extent than that of marriage. However, the countries that have granted the most extensive rights to registered couples are not always those where the law is the most widely used. Finally, the laws have been adopted in a general context of declining interest in marriage and widespread questioning of traditional family forms. Hence the hypothesis that this environment influences the attitude of the affected couples towards the new legislation.