In this article, we present and discuss the intended and unintended effects of the Swedish Sex Purchase Act, which criminalises the purchase of sex within a context where the sale of sex is legal. Whether or not this means of regulating prostitution is successful, and whether it has negative consequences for people who sell sex, are important questions in international policy and academic debates. This article builds on a scoping study aimed at identifying relevant sources of information as to the consequences of the Swedish Sex Purchase Act, then summarising and discussing these findings. The article offers policy makers and scholars a comprehensive presentation of the evidence and a discussion of the methodological, political and theoretical challenges arising from this.