The level of mixed marriage in a society indicates the openness of that society, since it shows the degree to which people from different social groups intermingle. In the Netherlands, mixed marriage once more attracts national attention because of the marriage between the Dutch Reformed Prince Willem-Alexander and the Catholic Argentinean Máxima Zorreguieta. Previous research has shown that, on average, spouses are quite similar with respect to social characteristics. Reasons for this phenomenon, known as homogamy, are sought in personal preferences and in preferences of the social environment such as parents and friends. The increasing rates of divorce make it both possible and interesting to focus on divorce. Do mixed marriages have a higher risk of ending up in divorce? The image of the openness of society will be extended and may have to be adapted, depending on the stability of mixed marriages. Couples can be mixed with regard to a number of social characteristics. Most of the limited research conducted on the relationship between mixed marriage and divorce only looked at one specific characteristic, or maybe a few, on which spouses may differ. In the present study, dimensions of six types of heterogamy are taken into account: regarding age, level of education, social status, religious affiliation, ethnicity and social origin. The author uses quantitative methods on two unique data sets: official marriage and divorce registrations and a survey among married and divorced people. In this way, he investigates the influence of mixed marriage on the risk of divorce in the Netherlands. Explanations for this influence, derived from the expected advantages of homogamy, are tested. Possible changes over the course of marriage and over time are investigated. The quality of spouse selection is assessed in the light of mixed marriage as well.