The identified trend of changing family relations and establishing a family without being traditionally married, probably does not apply to the entire Dutch population. Islamic law requires that people get married before children are born. Among Muslims, this standard is still followed on a large scale. Marriages which may be validly established according to Islamic law, however, will not always be recognized in the Netherlands. Examples include the unregistered marriages and polygamous marriages. This has implications for the way in which questions of parentage and custody of children that were born out of these marriages, are answered. In this article it will be argued that the law, where it concerns issues of parentage and custody, provides insufficient protection to the category of those unrecognized Islamic marriages.