In the late nineteenth century, abolitionist movements as well as the popular press lambasted the “white slave trade,” i.e. the national or international trafficking of women and forced prostitution practised by the official brothels. Many studies have focused on the abolitionists’ arguments and child prostitution as a public issue. However, the migrants and prostitutes’ individual trajectories remain largely overlooked. Based on an 1842 census of foreign prostotutes, this article highlights the great number of foreign minor women in the prostitution system since was implemented by the municipal authorities of Brussels. It also focuses on the consequences of such a phenomenon on women’s migration paths.