Trafficking in human beings, especially in women and children, is in fact trafficking in human misery. It represents one of the most horrible crime against humanity and it is increasing with every year (Bjelica, 2001; Cockburn, 2003). This paper will present definition of human traficking, some key features of this crime and the situation of this issue in the world and in Croatia. Human trafficking is one of the most lucrative forms of the organized crime, and it is believed that, because of the low risk and high profit, it is at the very top of organized crimes, just behind the drug and arms trafficking. The most common victims of this form of traffi cking are women and children, therefore the most vulnerable social groups. Because of the Croatian accession to the European Union and its economic and geographical position, human trafficking affects Croatia as a transit country, and almost equally as the country of origin or destination of human trafficking victims. As social work is increasingly becoming a profession based on human rights (establishment, study, implementation, protection, improvement), the focus of many programmes are those areas of the social work profession which, due to the process of integration, are being transformed into global challenges of the social work practice. In this paper, we will discuss various factors of prevention , where we will look at the challenges of social work in prevention and assistance to victims of trafficking .