Co-operation with the other Nordic countries has been a primary factor in the development of family law in Finland. Within the Nordic region, a Finnish, Swedish legal tradition is in evidence. This is derived from the period when Finland formed part of Sweden and was sustained after 1809 during Finland's incorporation within the Russian Empire. Maintenance of this association after Finnish independence in 1917 has been one facet of broader collaboration with Sweden. This study examines legal policy relating to the family from an institutional perspective. From this standpoint, regulation of domestic relationships is seen as an integral part of political culture. The article traces post-war developments in Finnish family law culminating in a marriage reform enacted in 1987. Analysis of differences in approach in Finland and Sweden to the institution of marriage highlights the extent to which legal policy in this sphere is an expression of political values and processes.