Prostitution policies in the Nordic countries have undergone major changes in the past 15 years. One that has drawn attention, within the Nordic region and internationally, is the criminalization of purchase of sexual acts or services in Sweden, Norway, and Iceland. Finland has criminalized buying sex from victims of trafficking or persons involved in pimp-organized prostitution. Laws concerning prostitution have to be understood in the light of how prostitution is defined and dealt with as a social problem. The recent changes can be explained by reference to ideological developments and developments in the prostitution market. That several countries have implemented similar regimes does not mean that the Nordic countries take a consistent approach. National policies have emerged from different ideological and empirical contexts and have been combined in diverse ways with different models for social work and other interventions