The article explores how Czechoslovakia reacted to the persistence of prostitution during State Socialism (1948-89) when its underlying Marxist-Leninist ideology predicted that it should disappear with the overthrow of capitalism. The paper adopts a law in context approach, critically analysing legal instruments as well as expert commentaries by social scientists, legal scholars, judges and prosecutors from the period. It argues that while the Czechoslovak state attempted to suppress prostitution through criminal law, conceptualising it as 'parasitism', many of the State Socialist experts ultimately fell back on the extra-legal normative system of gender. Women in prostitution were condemned for their sexually promiscuous behaviour while all women were blamed for failing in their gender roles as good women, wives and mothers. Whereas the official policy was thus enforcing socialist morality, the experts reverted to traditional bourgeois morality, in clear betrayal of the promises of both Marxism-Leninism and the State Socialist ideology as regards the equality of the sexes. The heightened responsibility all women were given to prevent prostitution was unique. State Socialist Czechoslovakia is thus more than yet another case study of a repressive regime that controls and punishes the more vulnerable side of the prostitution transaction and apportions blame in a gendered way. Instead, it demonstrates how prostitution can become a vehicle for promoting and upholding traditional gender norms not only towards women in prostitution, but all women in society.