Does stigma play a role on policy preferences in taboo markets? We argue that stigma toward sex workers constitutes an independent barrier to policy reform beyond moral opposition to taboo markets. Using a large-scale, nationally representative survey experiment in the United States, we separately measure taboo and stigma and randomly expose respondents to an information treatment on welfare gains, a stigma-reducing narrative, a placebo, or a neutral control. We elicit multidimensional measures of stigma—stereotypes, separation, status loss, and discrimination—as well as behavioral and attitudinal policy outcomes. We find that a stigma-focused narrative and taboo market information treatments reduced stigma and generate support for decriminalization. To our knowledge, this is the first study to explicitly identify and causally examine the role of stigma toward affected individuals in shaping policy preferences.